Saudi Arab has withdrawn from the Arab League monitoring mission in Syria amid accusations that the regime has continued to carry out violence against protesters.
Prince Saud al-Faisal, the Saudi foreign minister, called for the international community to increase pressure on the Assad regime to curb the 10-month crackdown on the demonstrators.
Addressing the 22 members of the Arab League at a meeting in Cairo, al-Faisal said: "My country will withdraw its monitors because the Syrian government did not execute any of the elements of the Arab resolution plan."
"We are calling on the international community to bear its responsibility, and that includes our brothers in Islamic states and our friends in Russia, China, Europe and the United States."
The League's meeting was expected to deliver a month long extension to the 165-strong mission in Syria. That was agreed however the Saudi diplomat announced his country's extrication minutes later, with Riyadh's withdrawal throwing into doubt the tenability of the League's ongoing task.
Soon after, Qatar demanded a review of the entire Syrian operation, with the Gulf States expected to follow Saudi Arabia's lead and withdraw their monitors.
Since the mission began, 22 monitors have quit, with the remainder spread across 17 locations. Despite initial reluctance by the regime, the Arab League supervisors have been given a degree of freedom to travel around the country, which observers suggest remains poised on the brink of civil war.
Speaking to Sky News, the Syrian deputy foreign minister said the Saudi's decision would not affect the mission, while refusing to accept that the protests are legitimate, calling the anti-regime demonstrations "the work or armed groups supported by neighbouring countries".
Saudi Arabia has long been a rival of the Iranian-backed Syrian regime, with commentators suggesting that their withdrawal from the mission is likely to be motivated more by politics than a genuine concern for Syrian opposition.