United Nations aid chief Valerie Amos has expressed concern for people cut off by months of fighting by government and rebel forces in Syria and called on the world to do more to help.
Amos said on a visit to the war-torn country's capital, Damascus, that she was particularly worried about reports of starvation and revealed talks had taken place with the Syrian government in an attempt to get access to those most in need.
Speaking ahead of a humanitarian donor conference for Syria to be hosted in Kuwait this week, Amos pleaded with the international community to ramp up efforts to assist Syrians living in dire conditions.
The war in Syria has claimed more than 100,000 lives since it began in March 2011 and forced more than two million to flee abroad, while another four million have been displaced inside the country.
"The world must do more for all the people who are displaced," she said, adding: "Many families are living in abandoned buildings, schools or in makeshift shelters, without enough food, clean water or medicine. We must help them to get through this very cold winter."
Meanwhile, the security situation on the ground is worsening, Amos said, as a result of fighting between different factions of the opposition forces.
CNN reported on Sunday that nearly 700 people have been killed in nine days of fierce clashes between an al Qaeda affiliate and other Islamist and rebel groups.
Amos' visit to Syria comes less than two weeks before the start of an international conference in Geneva which will aim to find a political solution to the war.
Foreign ministers from 11 countries which support the Syrian opposition movement met in Paris on Sunday with the aim of persuading the opposition to attend the Geneva II talks.