U.S. Secretary of State John Kerry met with Russian President Vladimir Putin about boosting military and intelligence cooperation against Daesh group (Islamic State) and al Qaeda in Syria and told him that without "concrete, near-term steps," diplomatic efforts to end the war could not go on indefinitely.
Kerry met Putin for three hours at the Kremlin and their talks lasted until 1 a.m. local time on Friday.
The State Department said Kerry expressed concern about repeated violations of a cessation of hostilities by the Moscow-backed Syrian government. It said the two also discussed the need to need to increase pressure on groups like Daesh and the Nusra Front, al Qaeda's affiliate in Syria.
Kerry "emphasized that absent concrete, near-term steps, diplomatic efforts could not continue indefinitely," a statement said, adding that discussions between Kerry and Russian Foreign Minister Sergei Lavrov on Friday were expected to explore initiatives in more detail.
On Thursday, the Washington Post published a leaked document it said Kerry would put forward in Moscow calling for intelligence sharing to identify leadership targets, training camps, supply lines and headquarters of the Nusra Front, al Qaeda's affiliate in Syria.
It said strikes against those targets could be carried out by U.S. or Russian jets and expanded coordination would be channeled through a Joint Implementation Group based in the vicinity of the Jordanian capital, Amman.
The extent of cooperation proposed in the document would represent a major U.S. shift after years of rivalry between Washington and Moscow, which support opposing sides in Syria's five-year civil war, but the idea has raised doubts among U.S. defense and intelligence officials.
Kerry declined to comment when asked about the document before leaving for Moscow.
Kremlin spokesman Dmitry Peskov said he would refrain from comment until Russian officials heard from Kerry, but that Russia in general favored cooperation with the United States over Syria.