Turkey suspended all activities at its embassy in the Syrian capital Damascus on Monday, further isolating President Bashar al-Assad,whose forces again bombarded the battered city of Homs withmortars in an effort to quell unrest.
Last year Turkish Prime Minister Tayyip Erdogan told Assad he should quit, having lost patience with his former friend's refusal to end a violent crackdown on popular unrest over the past year.
Turkey is providing sanctuary to more than 16,000 Syrians who have fled the violence in their homeland, has given shelter to soldiers from the rebel Free Syrian Army, and allows the Syrian opposition to meet regularly in Istanbul.
On April 1, Turkey will hold a meeting of "Friends of Syria", grouping mostly Arab and Western governments, to find ways to pressure Assad into halting his military clampdown, during which the country has drifted towards civil war.
Many of those governments closed their embassies in Damascus earlier this month.
The meeting of foreign ministers will be held in Istanbul, where leading Syrian dissidents were gathering on Monday and Tuesday in an attempt to bridge divisions within the opposition and instill confidence in the Syrian National Council umbrella organization.
More than 50 countries were represented at the first meeting of the "Friends of Syria" group in Tunis in late February.
Last week the foreign ministry called on all Turkish citizens in neighboring Syria to return to Turkey as soon as possible, saying it planned to close the consular section of its Damascus embassy, which it did on March 22.
All embassy staff have been withdrawn, including the ambassador, who had recently returned to Damascus, having earlier been brought back to Ankara for many months as relations with Assad's government turned icy.
Turkey, a Muslim member of NATO, has the second largest army in the Western alliance and has gathered increasing clout in the Middle East by siding with people rather than rulers during the uprisings that have shaken the Arab world since late 2010.
Turkish diplomats' families were brought home last year after an attack on the embassy by demonstrators who were angry that Turkey had taken sides against Assad.
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