The U.S. embassy in Syria is pulling out some of its staff due to the deteriorating security situation in the country, the State Department announced today.

U.S. Ambassador Robert Ford remains in country and officials say there has been no decision yet whether to close the embassy. Officials warn, however, that the reduction in staff will mean a reduction in the embassy's ability to provide American citizen and visa services. It also means that the American Language Center and the Damascus Community School will not be able to resume operations after the upcoming holiday break.

The move comes as the government's crackdown on protestors has become increasingly violent in recent days. According to one report, up to 250 people have been killed so far this week, including more than 100 people in one village. The opposition Syrian National Council says government forces surrounded and massacred nearly the entire town of Kfar Owaid.

The bloodshed took place just as Syria agreed to allow international monitors to enter and witness what is happening there. An advance team from the Arab League is expected to arrive on Thursday.

In an updated Travel Warning, issued late Wednesday, the State Department warned Americans to avoid travel to Syria and to depart immediately; those who must remain should limit their travel. The warning also noted the increased violence, which it said has spread to the capital of Damascus.

"Demonstrations, and violent government reactions to them, can occur with little or no warning anytime and anywhere," the warning said.

The regime of President Bashar al-Assad has intensified its crackdown on protestors who have demonstrated in the streets to seek his ouster since last spring. Some in the opposition have begun to fight back, but U.S. and opposition figures say most are unarmed and peaceful.

The Obama administration has matched Assad's escalating use of violence with increasingly harsh criticism and calls for action. Today the White House again called on Assad to step down, saying his promises of reform have "no credibility."

In a statement the White House called on Syria's remaining backers to abandon Assad and warned of additional steps should the regime not halt the violence.

"We urge Syria's few remaining supporters in the international community to warn Damascus that if the Arab League initiative is once again not fully implemented, the international community will take additional steps to pressure the Assad regime to stop its crackdown," the statement said.

The United States has been one of Assad's most vocal opponents. Ambassador Ford has defied restrictions on his movement throughout the country and visited a number of restive cities. In response, pro-Assad mobs have attacked the U.S. embassy and Ford's convoy on multiple occasions.

In late October, Ford was temporarily called back to Washington after what the U.S. says was a regime-sponsored campaign of incitement against him that threatened his safety. He returned in early December.

The U.S. has resisted calls from critics for a military intervention to prevent more bloodshed. Instead the Obama administration has advocated for monitors to be allowed in, suggesting that would prevent Assad's forces from doing their worst.

The administration has, however, reacted skeptically to Syria's agreement with the Arab League to allow monitors in, saying they'll believe it when they see it.