A Syrian defense ministry official declared Wednesday the halt of military operations in Syrian cities as of Thursday, according to official SANA news agency.

The unnamed official declared the move after "our army succeeded in its mission in fighting armed terrorist groups and regained full control over the territories."

The sources added that the armed forces would remain alert to retaliate against any attack to be launched by armed terrorist groups against civilians, law-enforcement agents and armed troops and against all public and private properties in order to protect the security of the homeland and citizens.

The announcement came in compliance with the deadline given by the United Nations for the implementation of a ceasefire brokered by the UN-Arab League joint special envoy Kofi Annan to solve the Syrian crisis politically and save the country from plunging into an all-out civil war.

Meanwhile, Annan said Wednesday that he had been informed by the Syrian government that the cease of all military fighting across Syria will go into effect as of 6 a.m. local time on Thursday, according to Annan's spokesman Ahamd Fawzi.

In a statement issued Wednesday, Fawzi said Syria's foreign minister has sent Annan a letter which said the government reserves "the right to respond proportionately to any attacks carried out by armed terrorist groups against civilians, government forces or public and private property."

The spokesman said that the international envoy will continue coordination with the Syrian government regarding the implementation of Annan's cease-fire plan.

The six-point plan calls for a troop withdrawal from populated areas by April 10 and a cease-fire by April 12. The plan aims to pave the way for a political settlement to the 13-month old unrest.

Syria is facing growing international pressure to end the alleged crackdown on opposition strongholds as the UN said more than 9,000 people have been killed over the yearlong crisis. But the Syrian government blames the unrest on armed groups working out a foreign conspiracy, which it said had claimed 6,044 lives, including 2,566 soldiers and police.