Destruction in Deir Ezzor
Destruction in Deir EzzorReuters

Syria's main opposition grouping said on Wednesday it would respect a provisional ceasefire in Syria "for two weeks", ahead of the proposed start of the truce this weekend.

"The High Negotiations Committee believes a provisional truce for two weeks would provide a chance to determine the commitment of the other side" to the ceasefire, the group said in a statement quoted by AFP.

Earlier this week, after the ceasefire was announced by the United States and Russia, the opposition said it would accept the deal only if certain humanitarian "conditions" were met.

At the time, the High Negotiations committee said those conditions are the lifting of sieges, release of prisoners, a halt to bombardment of civilians and the delivery of humanitarian aid.

The United States and Russia announced the cessation of hostilities in Syria on Monday, and said it will go into effect this Saturday on February 27.

In a joint statement, the two countries said Saturday's partial truce would begin at midnight Damascus time and would apply to parties to the conflict that have committed to the deal - but not to the Islamic State (ISIS) group or the Al-Nusra Front, an Al-Qaeda affiliate.

The agreement comes on the heels of another deal announced by top diplomats in Munich earlier this month, which was to go into effect last Friday.

The deadline of that ceasefire came and went with no end to the bloodshed in Syria.