The U.S. State Department announced on Monday that the United States has closed its embassy in Syria and pulled its remaining staff from the country.

Hundreds of Syrians flocked a main square in the capital Damascus on Feb. 5, 2012,? to voice support for President Bashar al-Assad, a day after the United Nations Security Council vetoed a draft resolution on Syria.?[Xinhua photo]

The U.S. has suspended operations of its embassy in Damascus as of Feb. 6. Ambassador Robert Ford and all American personnel have departed Syria, State Department spokeswoman Victoria Nuland said in a statement.

Nuland said that the decision to close the embassy came because "the regime failed to respond adequately" to U.S. security concerns, Xinhua reported.

The spokeswoman said Ford remains "the United States ambassador to Syria and its people," and would continue his work in Washington.

According to media reports, 17 American embassy employees, including Ford, left the country on Monday.

The reports, quoting a senior State Department official, said that deteriorating conditions in Syria made it impossible for the embassy to continue to operate.

The State Department last month said it was considering closing the embassy if the security issues were not addressed.

Ford was called back on Oct. 24 due to threats against him but returned on Dec. 6.

The State Department in October ordered family members of embassy staff in Damascus to leave. On Jan. 11, it ordered a further reduction in embassy staffing due to security concerns.

In an interview aired by NBC on Monday, U.S. President Barack Obama reiterated his call for Syrian President Bashar al-Assad to step down, saying "this is not going to be a matter of if, it's going to be a matter of when."

But when asked if there should be some kind of military intervention like there was in Libya, Obama said "Not every situation is going to allow for the kind of military solution we saw with Libya," adding that "it is very possible" to solve the Syrian crisis without outside military intervention.