GLOBAL POWERS agreed in Vienna yesterday to try to turn the current reduction in Syrian hostilities into a comprehensive ceasefire and to boost aid deliveries with the hope of restarting peace talks.

US Secretary of State John Kerry said that the participants had set a June 1 deadline for resumption of humanitarian aid shipments to areas cut off from the outside world.

He said that, if land routes remain blocked, food aid will be dropped by air and international pressure increased on those preventing such relief from getting through.

Mr Kerry reasserted his demand that Syrian President Bashar al-Assad must go.

Russian Foreign Minister Sergey Lavrov denied that Moscow’s support for Damascus constitutes unconditional backing for Mr Assad.

However, he stressed that Russia backs “the fight against terrorism and we don’t see a better alternative to doing that than the Syrian army.”