The deadline has passed for a ceasefire in Syria to come into effect as part of a peace plan proposed by Kofi Annan, the UN-Arab League peace envoy, but Western leaders have already expressed doubts about whether the Syrian government will honour the deal.Syria told Kofi Annan in a letter that it would halt all fighting by Thursday morning but reserved the right to respond to any attack by "armed terrorist groups”.Since rebels, loosely organised across Syria’s provinces, do not obey a set chain of command, there is no guarantee they will obey the ceasefire either.Al Jazeera’s Rula Amin, reporting from Beirut, said Annan "doesn’t expect a total halt of the violence” but wants to ensure at least enough room for humanitarian aid to arrive.On Thursday morning, activists in Syria and relaying information on Twitter reported no violence and calm streets in many flashpoint cities, though they expected attacks to resume.Saif, an activist in hard-hit Homs, told Al Jazeera that he thought shelling would resume within hours."All the shops are closed for more than two months, nobody is able to go to work, all communications except phone lines are disconnected in most of the areas, schools are closed also ... there are many difficulties,” he said.Abu Rami, another Homs activist, said that while shelling and attacks in the city in the hours before the ceasefire had "claimed the lives of dozens,” there had been no shootings or explosions on Thursday.Soldiers and armoured vehicles were still stationed at checkpoints, he said."I think many people will go down to the streets and keep protesting in their demonstrations and calling for their main goal, that this regime must step down,” he said.Suspicion and cynicismUS President Barack Obama and German Chancellor Angela Merkel agreed in a telephone call on Wednesday that "more resolute” UN Security Council action was needed on Syria, the White House said."The President and Chancellor shared the concern that the Assad government was not complying with the terms of the agreement negotiated by Kofi Annan and continued to engage in unacceptable brutality against its own people,” a White House statement said. "They agreed that this underscored the need for the UN Security Council to come together to take more resolute action.”The opposition also said there was no sign of compliance on the ground in the hours before the deadline as government forces pounded protest centres anew in violence that monitors said killed 14 civilians on Wednesday.Al Jazeera’s Cath Turner, reporting from the UN in New York, said the statement by the Syrian government "has been greeted with a great deal of suspicion and cynicism”."Susan Rice, the US ambassador to the UN, and the current president of the UN Security Council, spoke about the letter that has been submitted by president Assad, and she was very clear in the fact that she was not taking anything in that letter at its word, because, she said, President Assad did not have a very good track record at keeping his word,” our correspondent said.Iranian supportMeanwhile, Annan has welcomed Iranian support for his efforts to secure peace in Syria, telling Tehran that it can be "part of the solution”.