British diplomats have been withdrawn from Syria for "security reasons", William Hague said on Thursday.
The foreign secretary tweeted: "I have informed Parliament that I have withdrawn British diplomats from #Syria & suspended our Embassy there for security reasons."
In a statement to parliament, the foreign secretary said he had decided to suspend the services British Embassy in Damascus and take out all diplomatic staff.
"We have maintained an Embassy in Damascus despite the violence to help us communicate with all parties in Syria and to provide insight into the situation on the ground. Throughout this time we have kept the security situation of our staff and Embassy premises under intense and constant review. We now judge that the deterioration of the security situation in Damascus puts our Embassy staff and premises at risk, and have taken the decision to withdraw staff accordingly."
Hague said the ambassador Simon Collis had left Syria on 29 February. The retreat comes shortly after Egypt's ambassador withdrew.
British nationals still in Syria should contact EU embassies if they require assistance, the foreign office said.
Earlier the foreign secretary spoke out about reports Syrian troops were planning a new assault on the city of Homs, saying he was "appalled" by the claims.
"I call on those Syrians who are being ordered to attack their fellow citizens to make a choice and to lay down their arms. Those who do not do so will be held to account for their actions," he said.
The United Nation's rights council condemned Syria's "systematic violations" in a motto.
UN and Arab League appointed envoy to Syria Kofi Annan has said the diplomatic pores should go through one mediator.
"If we are going to succeed it is extremely important that we all accept that there should be one process of mediation."
It comes as Number 10 said David Cameron will raise Syria at Thursday's European Council summit in Brussels.
"Clearly, thousands of people are losing their lives in this terrible situation. Any way forward has got to be through peaceful means. We have got sanctions in place and we want to make sure that those people who have committed atrocities and crimes face up to those crimes," a Downing Street spokesperson said.