UN envoy appeals to US, Russia to help Syria peace talks

FILE-- In this Fiday April 22, 2016, file photo, UN special envoy for Syria envoy Staffan de Mistura, right, and his deputy Ramzy Ezzeldin Ramzy attend a meeting with the Syrian government delegation during Syria peace talks at the United Nations office in Geneva, Switzerland. A military buildup in northern Syria coupled with heavy fighting and mounting civilian casualties spells the end of a cease-fire that for two months brought much needed relief to war-stricken Syrians, ushering in what could be an even more ruinous chapter in the country's five-year-old conflict. (Fabrice Coffrini/Pool Photo via AP, File) (The Associated Press)

UN Special Envoy for Syria Staffan de Mistura, center, gestures prior a round of negotiations between Syria's regime-tolerated opposition and the U.N. at the European headquarters of the United Nations in Geneva, Switzerland, Wednesday, April 27, 2016. (Martial Trezzini/Pool Photo via AP) (The Associated Press)

GENEVA – The U.N. envoy for Syria is appealing to the U.S. and Russia to intervene "at the highest level" to help revive ailing Syrian peace talks without setting a date for them to resume.

Staffan de Mistura spoke to reporters early Thursday after briefing the U.N. Security Council via videoconference about the largely stalled talks. He said he hoped talks could resume sometime in May but suggested it would first require a reduction in fighting.

The briefing came at the end of a third session of talks this year.

The opposition suspended its formal role in the indirect talks with President Bashar Assad's government last week to protest alleged government cease-fire violations, a drop in humanitarian aid deliveries and no progress in winning the release of detainees in Syria.