GENEVA (Reuters) - U.N. Syria envoy Staffan de Mistura said on Tuesday he aimed to convene a new round of Syria peace talks toward the end of August, quietly scrapping a previous timeline while putting down a new deadline for a U.S.-Russia deal to support the talks.

De Mistura, speaking after a meeting with U.S. Syria envoy Michael Ratney and Russian Deputy Foreign Minister Gennady Gatilov, said the United States and Russia both needed to do more work in the coming days.

De Mistura said the trilateral meeting in Geneva focused on the urgent need for progress on Syria's cessation of hostilities, access for humanitarian aid, counter-terrorism and political transition.

(Reporting by Tom Miles and Stephanie Nebehay)