Yemen peace talks will begin on Thursday in Kuwait, the United Nations confirmed, after the rebels finally agreed to join the negotiating table.

"The Yemeni peace negotiations will start tomorrow in Kuwait under the auspices of the United Nations," said UN spokesman Stephane Dujarric.

The talks had been set to open in Kuwait on Monday but were put off after the Shia Houthi rebels failed to show up.

A delegation of rebels left Sanaa on Wednesday for Kuwait after the United Nations offered assurances that government forces would abide by a ceasefire that went into force on April 11.

Yemen slid deeper into chaos when a Saudi-led coalition launched air strikes in March 2015 to push back the Houthi offensive.

The United Nations says more than 6,400 people have been killed in the conflict and almost 2.8 million forced from their homes.