US President Barack Obama has urged his Russian counterpart Vladimir Putin to end air strikes against Syrian opposition forces, the White House has said.
In a phone call with Mr Putin yesterday, Mr Obama stressed the need to quickly get humanitarian aid to besieged areas and initiating the cessation of hostilities across the war-wracked country, the White House statement said.
"In particular, President Obama emphasised the importance now of Russia playing a constructive role by ceasing its air campaign against moderate opposition forces in Syria," the statement said.
The call came in the wake of a truce deal forged on Friday by Washington and Moscow that has been criticised by the Syrian opposition, which accuses Russia of continuing bombings of civilian areas.
Mr Obama also raised Russia's conflict with Ukraine in the call to Mr Putin, urging "combined Russian-separatist forces" to adhere to a ceasefire and ensure that monitors from the Organisation for Security and Cooperation in Europe have "full access to all areas of eastern Ukraine, including the international border".
Ukrainian President Petro Poroshenko said yesterday that Russian troops, weapons and ammunition were entering Ukraine every day.
"Mr Putin, this is not a civil war in Ukraine, this is your aggression," he said.
His remarks came as US Secretary of State John Kerry said Moscow must pull its troops out of Ukraine and that sanctions on Russia would remain in place until it implements all aspects of the Ukraine peace agreement reached in Belarus last year.
Meanwhile, Turkey will continue to strike back at Kurdish fighters of the Democratic Union Party (PYD) in Syria, Prime Minister Ahmet Davutoglu told German Chancellor Angela Merkel today, despite growing pressure on Ankara to stop the shelling.
In telephone talks, Mr Davutoglu told Ms Merkel that Turkey "will not permit the PYD to carry out aggressive acts. Our security forces gave the necessary response and will continue to do so," his office said in a statement.
Turkish artillery struck at targets of the PYD and its People's Protection Units (YPG) militia on both days of the weekend, while insisting that it was returning fire under the rules of engagement.