Syrian rebels could be armed by the UK in a fresh push to oust President Bashar Assad and end the bloodshed after David Cameron ordered officials to re-examine all options.

A Downing Street official said the prime minister wanted to put previously rejected measures "back on the table" amid frustration at the failure to halt the 20-month conflict.

On Wednesday, Cameron vowed to redouble his efforts after visiting a refugee camp in Jordan and hearing "horrendous" stories of some of those who have fled the violence.

mohammed osama laham

Arming rebels is one method being considered in new efforts to end the war

British diplomats are already set for talks with opposition military commanders as part of the renewed drive - which the premier said should be a top priority for the re-elected US president Barack Obama.

He insisted during a three-day Middle East tour that Britain has no plans at present to directly arm rebel forces, pointing out that it was prohibited under the terms of a European Union arms embargo.

However, Whitehall officials are said to be considering whether it could be justified under United Nations resolutions and sounding out potential support within Europe for amending the current restrictions.

syria rebels

Fighting has raged in the country for almost two years

Other possibile new approaches are the creation of United Nations-enforced "safe zones" within Syria's own borders for refugees - a move being urged on the UN by neighbouring Turkey.

Downing Street later confirmed that while there were no plans for Britain to arm the rebels, officials were not ruling out any options for the future.

"We are frustrated by what is happening in Syria, we are frustrated by the fact that the regime is still in place and has not stopped the killing," the prime minister's spokesman said.

"We should not be ruling out options for the future."

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  • David Cameron Visits Syrian Refugee Camp

    ZAATARI, JORDAN - NOVEMBER 7: British Prime Minister David Cameron (4th L) arrives at Al Zaatari camp for Syrian refugees , on November 7, 2012 in north east Jordan. The camp sees some 500 people arriving daily and Cameron is thought to the first G20 leader to have visited. Cameron's visit comes ahead of talks with armed Syrian rebels. (Photo by Salah Malkawi/Getty Images)

  • JORDAN-BRITAIN-SYRIA-REFUGEES

    British Prime Minister David Cameron (C-L), Jordanian Foreign Minister Nasser Judeh (C-R) and United Nations High Commissioner for Refugees (UNHCR) representative to Jordan Andrew Harper (R) walk in the Zaatari refugee camp in the Jordanian town of Mafraq, near the border with Syria, on November 7, 2012. Cameron vowed to do more to help end the bloody crisis in Syria as he made a surprise visit to the sprawling Zaatari refugee camp following a three-day Middle Eastern tour. AFP PHOTO/STR (Photo credit should read KHALIL MAZRAAWI/AFP/Getty Images)

  • David Cameron Visits Syrian Refugee Camp

    ZAATARI, JORDAN - NOVEMBER 7: British Prime Minister David Cameron (C) arrives at Al Zaatari camp for Syrian refugees , on November 7, 2012 in north east Jordan. The camp sees some 500 people arriving daily and Cameron is thought to the first G20 leader to have visited. Cameron's visit comes ahead of talks with armed Syrian rebels. (Photo by Salah Malkawi/Getty Images)

  • David Cameron Visits Syrian Refugee Camp

    ZAATARI, JORDAN - NOVEMBER 7: British Prime Minister David Cameron (C) arrives at Al Zaatari camp for Syrian refugees , on November 7, 2012 in north east Jordan. The camp sees some 500 people arriving daily and Cameron is thought to the first G20 leader to have visited. Cameron's visit comes ahead of talks with armed Syrian rebels. (Photo by Salah Malkawi/Getty Images)

  • David Cameron Visits Syrian Refugee Camp

    ZAATARI, JORDAN - NOVEMBER 7: British Prime Minister David Cameron (C) arrives at Al Zaatari camp for Syrian refugees , on November 7, 2012 in north east Jordan. The camp sees some 500 people arriving daily and Cameron is thought to the first G20 leader to have visited. Cameron's visit comes ahead of talks with armed Syrian rebels. (Photo by Salah Malkawi/Getty Images)

  • David Cameron Visits Syrian Refugee Camp

    ZAATARI, JORDAN - NOVEMBER 7: Syrian refugees watch as British Prime Minister David Cameron (not pictured) arrives at Al Zaatari camp for Syrian refugees , on November 7, 2012 in north east Jordan. The camp sees some 500 people arriving daily and Cameron is thought to the first G20 leader to have visited. Cameron's visit comes ahead of talks with armed Syrian rebels. (Photo by Salah Malkawi/Getty Images)

  • David Cameron Visits Syrian Refugee Camp

    ZAATARI, JORDAN - NOVEMBER 7: Syrian refugee children watch as British Prime Minister David Cameron (not pictured) arrives at Al Zaatari camp for Syrian refugees , on November 7, 2012 in north east Jordan. The camp sees some 500 people arriving daily and Cameron is thought to the first G20 leader to have visited. Cameron's visit comes ahead of talks with armed Syrian rebels. (Photo by Salah Malkawi/Getty Images)

  • David Cameron Visits Syrian Refugee Camp

    ZAATARI, JORDAN - NOVEMBER 7: Syrian refugee children watch as British Prime Minister David Cameron (not pictured) arrives at Al Zaatari camp for Syrian refugees , on November 7, 2012 in north east Jordan. The camp sees some 500 people arriving daily and Cameron is thought to the first G20 leader to have visited. Cameron's visit comes ahead of talks with armed Syrian rebels. (Photo by Salah Malkawi/Getty Images)

  • David Cameron Visits Syrian Refugee Camp

    ZAATARI, JORDAN - NOVEMBER 7: British Prime Minister David Cameron (L) arrives at Al Zaatari camp for Syrian refugees , on November 7, 2012 in north east Jordan. The camp sees some 500 people arriving daily and Cameron is thought to the first G20 leader to have visited. Cameron's visit comes ahead of talks with armed Syrian rebels. (Photo by Salah Malkawi/Getty Images)

  • Cameron visit to the Gulf States

    Prime Minister David Cameron talks to a refugee from Syria in the reception centre at the Za'atri refugee camp near the Syrian - Jordanian border where he met Syrian families who have escaped across the border into Jordan from the Assad regime.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets King Abdullah of Jordan at the Royal Palace in Amman today. Earlier he visited the Za'atri refugee camp near the Syrian - Jordanian border where he met Syrian families who have escaped across the border into Jordan from the Assad regime.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron tours the Za'atri refugee camp near the Syrian - Jordanian border where he met Syrian families who have escaped across the border into Jordan from the Assad regime.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets King Abdullah of Jordan at the Royal Palace in Amman today. Earlier he visited the Za'atri refugee camp near the Syrian - Jordanian border where he met Syrian families who have escaped across the border into Jordan from the Assad regime.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron talks to border guards on the Syrian - Jordanian border near the Al Wahdah dam. Mr Cameron saw the path taken by Syrian refugees and he later went to the Za'atri camp and met Syrian families who have escaped across the border.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron talks to border guards on the Syrian - Jordanian border near the Al Wahdah dam. Mr Cameron saw the path taken by Syrian refugees and he later went to the Za'atri camp and met Syrian families who have escaped across the border.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron looks into Syria from the Jordanian border near the Al Wahdah dam. Mr Cameron saw the path taken by Syrian refugees and he later went to the Za'atri camp and met Syrian families who have escaped across the border.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets children and teachers in a classroom at the Za'atri refugee camp near the Syrian - Jordanian border where he met Syrian families who have escaped across the border into Jordan from the Assad regime.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets children and teachers in a classroom at the Za'atri refugee camp near the Syrian - Jordanian border where he met Syrian families who have escaped across the border into Jordan from the Assad regime.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets female students at Dar Al-Hekma University in Jeddah during his one day visit to Saudi Arabia today. Earlier Cameron met King Abdullah at his official residence.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets female students at Dar Al-Hekma University in Jeddah during his one day visit to Saudi Arabia today. Earlier Cameron met King Abdullah at his official residence.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron tours the Za'atri refugee camp near the Syrian - Jordanian border where he met Syrian families who have escaped across the border into Jordan from the Assad regime.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets female students at Dar Al-Hekma University in Jeddah during his one day visit to Saudi Arabia today. Earlier Cameron met King Abdullah at his official residence.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets female students at Dar Al-Hekma University in Jeddah during his one day visit to Saudi Arabia.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets female students at Dar Al-Hekma University in Jeddah during his one day visit to Saudi Arabia.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets female students at Dar Al-Hekma University in Jeddah during his one day visit to Saudi Arabia today. Earlier Cameron met King Abdullah at his official residence.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets King Abdullah of Jordan at the Royal Palace in Amman today. Earlier the PM visited the Za'atri refugee camp near the Syrian - Jordanian border where he met Syrian families who have escaped across the border into Jordan from the Assad regime.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron receives the King Abdullah Decoration One from King Abdullah of Saudi Arabia at the Palace of the King in Jeddah today.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron receives the King Abdullah Decoration One from King Abdullah of Saudi Arabia at the Palace of the King in Jeddah today.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets King Abdullah of Saudi Arabia at the Palace of the King in Jeddah today accompanied by Defence Secretary Philip Hammond (left).

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets King Abdullah of Saudi Arabia at the Palace of the King in Jeddah today.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets King Abdullah of Saudi Arabia at the Palace of the King in Jeddah today accompanied by Defence Secretary Philip Hammond (left).

  • Cameron visit to the Gulf States

    Prime Minister David Cameron at the Palace of the King in Jeddah today where he met King Abdullah of Saudi Arabia.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron receives the King Abdullah Decoration One from King Abdullah of Saudi Arabia at the Palace of the King in Jeddah today.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets King Abdullah of Saudi Arabia at the Palace of the King in Jeddah today.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron receives the King Abdullah Decoration One from King Abdullah of Saudi Arabia at the Palace of the King in Jeddah today.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets King Abdullah of Saudi Arabia arrives in Jeddah greeted by the Governor of Mecca, Khalid al Faisal. Later he went onto to meet King Abdullah at the Palace of the King where they had lunch and bilateral meetings.

  • David Cameron, Khalifa bin Zayed

    In this handout photos made available by Emirates News Agency, WAM, British Prime Minister David Cameron, right, shakes hands with President of the UAE, Sheikh Khalifa bin Zayed at al Nahyan at Al Rawda Palace in the city of al Ain in Abu Dhabi, United Arab Emirates, Tuesday, Nov. 6, 2012. Cameron is on a three day visit to Gulf states. (AP Photo/WAM)

  • David Cameron, Khalifa bin Zayed

    In this handout photos made available by Emirates News Agency, WAM, British Prime Minister David Cameron, fifth left, walks with with President of the UAE, Sheikh Khalifa bin Zayed at al Nahyan, fifth right, at Al Rawda Palace in the city of al Ain in Abu Dhabi, United Arab Emirates, Tuesday, Nov. 6, 2012. Cameron is on a three day visit to Gulf states. (AP Photo/WAM)

  • Cameron visit to the Gulf States

    Prime Minister David Cameron is welcomed by Government ministers to the Al Rawda Palace in the city of al Ain in Abu Dhabi after meeting President of the UAE HH Sheikh Khalifa bin Zayed al Nahyan where they held a bilateral meeting, during his three day visit to Gulf states.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron is welcomed to the Al Rawda Palace in the city of al Ain in Abu Dhabi by the President of the UAE HH Sheikh Khalifa bin Zayed al Nahyan where they held a bilateral meeting. Cameron is on a three day visit to Gulf states.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron is welcomed to the Al Rawda Palace in the city of al Ain in Abu Dhabi by the President of the UAE HH Sheikh Khalifa bin Zayed al Nahyan where they held a bilateral meeting. Cameron is on a three day visit to Gulf states.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron is welcomed by Government ministers to the Al Rawda Palace in the city of al Ain in Abu Dhabi after meeting President of the UAE HH Sheikh Khalifa bin Zayed al Nahyan where they held a bilateral meeting, during his three day visit to Gulf states.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron (left) and Defence Secretary Philip Hammondn (right) talk with the President of the UAE HH Sheikh Khalifa bin Zayed al Nahya, at the Al Rawda Palace in the city of al Ain in Abu Dhabi, where they held a bilateral meeting, as part of a three day visit to Gulf states.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets students at Zayed University in Abu Dhabi before holding a Q&A with 350 more students where he faced questions about a range of topics including the 'arab spring'.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets students at Zayed University in Abu Dhabi before holding a Q&A with 350 more students where he faced questions about a range of topics including the 'arab spring'.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets students at Zayed University in Abu Dhabi before holding a Q&A with 350 more students where he faced questions about a range of topics including the 'arab spring'.

  • Cameron visit to the Gulf States

    Students at Zayed University take part in a Q&A with Prime Minister David Cameron in Abu Dhabi today where he faced questions about a range of topics including the 'arab spring'.

  • Cameron visit to the Gulf States

    Students at Zayed University take part in a Q&A with Prime Minister David Cameron in Abu Dhabi today where he faced questions about a range of topics including the 'arab spring'.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron meets students at Zayed University in Abu Dhabi before holding a Q&A with 350 more students where he faced questions about a range of topics including the 'arab spring'.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron holds a Q&A with 350 students at Zayed University in Abu Dhabi today where he faced questions about a range of topics including the 'arab spring'.

  • Cameron visit to the Gulf States

    Prime Minister David Cameron holds a Q&A with 350 students at Zayed University in Abu Dhabi today where he faced questions about a range of topics including the 'arab spring'.