Leaders of Syria's embattled opposition reacted with bitter scorn Monday, accusing the world of ignoring their people's plight as a week-long truce in their country's civil war collapsed.

Addressing a political meeting on the sidelines of the UN General Assembly, the head of the opposition umbrella group known as the High Negotiations Committee (HNC) said the ceasefire had never been respected anyway. 

"Enough is enough," Riad Hijab told international diplomats. "The world is content to look on without reacting, when it should assume its responsibilities and put an end to the actions of this criminal regime."

The 23-nation International Syria Support Group (ISSG) is to meet in New York on Tuesday to push for a negotiated end to the five-year-old war that has left more than 300,000 Syrians dead and driven millions from their homes.

But already on Monday, Syrian leader Bashar al-Assad's military had announced an end to a week-old ceasefire that was negotiated between Washington, which backs the rebels, and Moscow, which favors the regime.  

"How many UN Security Council resolutions have been passed? They were in vain," Hijab declared. 

"Russia and Iran are spilling Syrian blood, the regime bombards hospitals and drops thousands of barrel bombs and other banned weapons. The world just looks on."

US Secretary of State John Kerry said he is ready to reopen negotiations with Russia to salvage the truce and ensure the regime allows aid convoys into besieged towns, but HNC spokesman Monzer Makhous warned he could see "little chance" of a ceasefire succeeding again.

Source: AFP