Russia and the United States have begun discussing the fall of President Assad amid signs that Syria’s four-year civil war is turning decisively against him, The Times reported.

Intelligence reports suggest that recent battlefield gains by rebel groups have left the Syria dictator looking more vulnerable than at any point since 2011.

When John Kerry, the US secretary of state, met his Russian counterpart Sergei Lavrov this week, Moscow was not ready to drop its long-standing support for Assad.