The Latest on the war in Syria (all times local):

12:05 p.m.

A senior Russian diplomat says Moscow views a cease-fire in Syria as the best option possible.

Deputy Foreign Minister Sergei Ryabkov says Thursday, according to Russian news agencies, that Moscow sees no alternative to the U.S.-Russia-brokered cease-fire in Syria. The truce declared Sept. 12 has been on the verge of collapse amid fighting around Aleppo and an attack on a humanitarian convoy.

Ryabkov said the deal was the best possible option amid sharp disagreements over Syria, adding that Russian and U.S. diplomats need to "calmly sit down and think what needs to be done to keep the agreement afloat."

He added that the rebels have sabotaged the agreement and noted that Washington has failed to meet its pledge to encourage moderate rebels to disengage themselves from terrorist groups.


10 a.m.

The United States and Russia are taking their differences over the conflict in Syria to new heights, after trading ferocious allegations of duplicity and malfeasance at the United Nations Security Council in New York.

After a fractious meeting of the council on Wednesday, Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov were set to duel again over Syria at a gathering of the roughly 20 nations that have an interest in Syria.

Thursday's meeting of the International Syria Support Group comes after the two men blamed each other for spoiling the country's cease-fire that they had agreed to earlier this month. Each has blamed the other for violations.

Kerry called for all warplanes to halt flights over aid routes, while Lavrov suggested a possible three-day pause in fighting to get the truce back on track.