The U.S. has closed its embassy in Damascus in a move which increased diplomatic pressure on the Syrian regime as President Barack Obama declared he opposed military intervention.

The withdrawal on Monday of the ambassador Robert Ford and the 17 remaining staff comes amid increasingly brutal attempts by Syrian security forces to put down uprisings in Homs and other cities.

The U.S. State Department said the move reflected 'serious
concerns that our embassy is not protected from armed
attack' in Syria. Photograph: Muzaffar Salman/AP

The U.S. State Department said the move reflected "serious concerns that our embassy is not protected from armed attack". Those concerns were heightened by two car bomb attacks on state security offices in Damascus last month.

The Syrian government was informed that the embassy had been closed only after Ford and his staff had left the country. Two left by air while the others crossed into neighboring Jordan by road.

In the face of calls for stronger action after Russia and China vetoed a U.N. Security Council resolution targeting the Bashar Assad's government, Obama said he did not favor replicating the NATO bombing campaign that helped topple Moammar Ghaddafi in Libya in part because of a lack of consensus among the major powers.