Russia and the United States discussed the Syrian conflict in New York, hours after clashing over the issue at the United Nations, the Russian foreign ministry said Thursday.

US Secretary of State John Kerry and his Russian counterpart Sergei Lavrov talked first by telephone "at the initiative of the Americans", the ministry said in a message on Facebook.

The diplomats then met, accompanied by their delegations, "to continue discussing the problem of a settlement (of the conflict) in Syria."

Russia and the United States negotiated the latest ceasefire plan, but Syria ended the truce on Monday following an apparently accidental US-led coalition strike on Syrian soldiers.

Shortly after the truce ended, a UN aid convoy was hit, killing 20 humanitarian workers and destroying 18 trucks carrying food for desperate civilians in Aleppo province.

On Wednesday, an angry Kerry demanded at a UN Security Council meeting that Russia force Syria to ground its air force, which Washington blames for the attack on the aid convoy.

Kerry said the bombing raised "profound doubt" about whether Russia and its Syrian ally were committed to upholding a ceasefire.

In his address to the Security Council, Lavrov declared on Wednesday that there would be "no more unilateral pauses" by Syrian government forces, arguing that opposition fighters on the ground had previously used those ceasefires to regroup.

He insisted that all sides must rein in rebel groups on the ground to ensure they comply with the ceasefire and said a list of terror groups not covered by the truce should be reviewed.

The United States and Russia are to chair a meeting in New York later on Thursday of the 23-nation International Syria Support Group (ISSG), which brings together world powers with a stake in the civil war.