US Secretary of State John Kerry is still pursuing an agreement with Russia on military cooperation in the fight against ISIL in Syria despite major setbacks and skepticism from other administration officials and US allies

US Secretary of State John Kerry is still pursuing an agreement with Russia on military cooperation in the fight against ISIL in Syria despite major setbacks and skepticism from other administration officials and US allies, US officials with knowledge of the talks said on Friday.

"We believe this approach is still worth pursuing," State Department spokesman John Kirby said in an email response to Reuters questions, adding: "But it remains to be seen whether or not we can get there. "Kerry has been pursuing a proposal that envisions resuscitating a Cessation of Hostilities agreement, creating a center where the two countries would share intelligence for targeting air strikes, and prohibiting the Syrian air force from attacking US-backed terrorist groups.

Instead, Syrian and Russian warplanes have continued to pound terrorists who are attacking the northern city of Aleppo.

"We've been very concerned about the situation in Aleppo and we have made those concerns plain to Russian officials," said Kirby, who noted that Kerry had spoken to his Russian counterpart, Sergei Lavrov, in a phone call on Friday.

Speaking in Laos last week, Kerry said he hoped for an agreement early in August, but two US officials said on Friday there had been "limited progress" toward a deal.

"Discussions will likely continue, but there is no illusion on how much can be achieved," said another US official, speaking on condition of anonymity.