Russia called for more time on Thursday for international envoy Kofi Annan's Syrian peace plan to work, as a ceasefire to end months of violence came into force with no major reports of violations.

Foreign Minister Sergei Lavrov said some Arab and Western states had written off Annan's peace plan as a failure even before it had gone into effect and called on them to use their influence with the rebels to avoid future unrest.

UAE Foreign Minister Sheikh Abdullah bin Zayed al-Nahayan slammed a visit by Iranian President Mahmoud Ahmadinejad to a disputed island, state news agency WAM said.

"Sheikh Abdullah blasted the visit as a 'flagrant violation' of UAE sovereignty over its territories and a setback to all efforts and attempts the UAE is making to find a peaceful settlement to Iran's occupation of the three UAE islands," WAM reported late on Wednesday.

The head of the opposition Syrian National Council on Thursday urged people to demonstrate against President Bashar Assad's regime, in a test of a ceasefire that entered in to force at dawn.

Burhan Ghalioun, who leads the exile umbrella opposition organization, also urged the international community to provide protection to Syrians who take to the streets by sending observers.

Salafist politician Hazem Abu Ismail looks set to rejoin the presidential race after a court ruled on Wednesday that his mother was not a U.S. citizen, the official MENA news agency reported.

Under the country's electoral law, all candidates for the presidency, their parents and their wives must have only Egyptian citizenship.

NATO said Thursday it takes its responsibility to defend allies "extremely seriously" after member state Turkey said it may seek help after shootings along its border with Syria.

"We are deeply concerned by events in Syria, particularly the recent incidents on the border with our ally Turkey," NATO spokeswoman Carmen Romero told Agence France Presse.

British Prime Minister David Cameron urged Russia and China on Thursday to join the international community and help "tighten the noose" on the Syrian regime over its deadly crackdown on protests.

A U.N.-backed ceasefire to end 13 months of bloodshed in Syria appeared to be holding after coming into force at daybreak, but doubts remained about the compliance of President Bashar Assad's government with the peace plan.

China's foreign ministry on Thursday welcomed what it called the Syrian government's decision to uphold a "comprehensive ceasefire,” and urged it to fulfill its commitments.

"This will help ease the tense situation in Syria, and is an important step towards a political solution," said ministry spokesman Liu Weimin, after a U.N.-backed ceasefire to end 13 months of bloodshed in Syria came into force.

A ceasefire in Syria appeared to be holding on Thursday, as the Syrian government and its foes traded charges of trying to wreck U.N.-Arab League envoy Kofi Annan’s peace plan.

Renewed bloodshed on Thursday killed at least 23 people, putting to the test the hard-won ceasefire plan.

German Foreign Minister Guido Westerwelle Wednesday pressed Russia to distance itself from Syrian President Bashar al-Assad's deadly crackdown on opposition rebels.

"Russia has to make clear that it does not want to have anything to do with these acts of violence and this repression," Westerwelle said on the sidelines of a two-day meeting with Group of Eight ministers in Washington.

U.S. Secretary of State Hillary Clinton said Wednesday she is alarmed about the "ongoing violence" in Syria on the eve of a ceasefire deadline.

In remarks to the Group of Eight foreign ministers, she also voiced concern about the problems facing U.N.-Arab League envoy Kofi Annan as he tries to get Syria to implement his peace plan that calls for a ceasefire on Thursday.