UN-led peace talks between warring Yemeni factions began Monday in Switzerland, as a Saudi-led coalition continued air strikes against Houthi rebels in the capital Sana'a overnight.
U.N. Secretary-General Ban Ki-moon called for pro-government forces and rebels to observe a humanitarian cease-fire of at least two weeks during the Muslim holy month of Ramadan. He said it should be "a time for peace, reflection and harmony." Ramadan begins later this week.
Ban spoke in Geneva, where his Yemen envoy Ismail Ould Cheick Ahmed was due to hold separate meetings with delegations from the exiled government of President Abd Rabbu Mansour Hadi and the Houthi rebels who control Yemen's capital.
"Today, Yemen's very existence hangs in the balance," said Ban. "While parties bicker, Yemen burns."
The peace talks are the first diplomatic bid to resolve the conflict since it escalated three months ago into a regional fight, but the proceedings are not expected to include face-to-face meetings.
Yemeni Foreign Minister Reyad Yassin Abdulla said Monday his government would discuss a cease-fire with Houthis only if the militia pulled out of cities, released thousands of prisoners, and agreed to a UN resolution.
Ban has called on both sides to enter the process with no preconditions and said he hopes the meeting will restart a peaceful political transition in Yemen. He said Monday morning that the Houthi delegation was delayed in arriving, but was expected later in the day.
Yemen has been in political upheaval since 2011 when protesters forced longtime President Ali Abdullah Saleh from power. Saleh now backs the Houthis.
Houthi fighters swept from Sana'a south to the port city of Aden in late March, sending Hadi fleeing to neighboring Saudi Arabia. In response, Saudi Arabia began leading a coalition conducting airstrikes against the Houthis at Hadi's request.
The U.N. Security Council adopted a resolution in April demanding the Houthis stop their violence and withdraw from areas they have seized, including Sana'a. It also called on all sides to facilitate the delivery of humanitarian aid to civilians affected by the conflict.
Last week, the U.N. said 21 million of Yemen's 26 million people were in need of aid, and that the fighting had forced 1 million people from their homes.
The conflict has killed more than 2,500 people and injured 11,000 others.