U.S. Secretary of State John Kerrysaid on Tuesday he hoped to announce in early August details of a U.S. plan for closer military cooperation and intelligence sharing with Russia on Syria.

Kerry, speaking after meeting with Russian Foreign Minister Sergei Lavrov on the sidelines of a meeting of Southeast Asian nations in Laos, said there had been progress in recent days on moving forward with the plan.

The proposal would have Washington and Moscow share intelligence to coordinate air strikes against the al Qaeda-affiliated Nusra Front and prohibit the Syrian air force from attacking moderate rebel groups.

In Geneva, U.N. Special Envoy Staffan de Mistura said he aimed to convene a new round of Syria peace talks toward the end of August, quietly scrapping a previous Aug. 1 deadline while keeping some time pressure on the U.S.-Russia deal.