Putin trumpets Russian leadership with the launch of airstrikes that appear to hit anti-Assad forces.
Fear that the conflict could get even worse is precipitating a host of military and diplomatic moves.
Raúl Castro has done little to open Cuba’s economy since diplomatic relations resumed, U.S. officials said.
The two rivals faulted each others’ policies at the U.N. but left the door open for cooperation on the civil war.
Putin and Obama will meet Monday evening for their first extended one-on-one session in over a year.
The Russian presidents points to interventions in Syria and Libya as failed efforts to impose democracy.