UN mediator Staffan de Mistura said Tuesday (June 21st) he hopes that stalled Syrian peace talks can resume in July, but only if the security and humanitarian situation on the ground shows clear improvement, AFP reported.

The UN-backed talks aim to reach a political settlement to Syria's war, but the process has deadlocked while on the ground a fragile truce hangs by a thread.

"The window of opportunity is coming quickly to a close unless we maintain alive the cessation of hostilities, we increase humanitarian aid and we come to some common understanding of a political transition," de Mistura told the General Assembly via video link from Geneva.

"Then we can have, hopefully in July, inter-Syrian talks that are not about principles but about concrete steps to a political transition," he said. "I will consider that in July but not yet, not now because it is premature in view of the current discussions and current situation."

The US and Russia, co-chairs of the 22-nation International Syria Support Group (ISSG) steering the peace process, have set a target of August 1st to begin substantive talks between the regime and the non-extremist Syrian opposition on a political transition.