Yemen's Houthi movement failed to attend peace talks, but the U.N. Special Envoy said on Saturday that it did not represent a "fundamental blockage in the process" and that he would meet soon with their representatives in Sanaa and in Muscat, Oman.

"They would have like to get here, we didn't make conditions sufficiently correct to get them here", U.N. envoy Martin Griffiths told a news conference, declining to elaborate.

Agreement has been reached for medical evacuations from the Houthi-held Yemeni capital of Sanaa, to start in a week with a flight to Cairo, he said.