SANAA — Yemen’s warring factions confirmed their agreement on Thursday to a temporary humanitarian ceasefire set to begin on Friday night, United Nations envoy Ismail Ould Cheikh Ahmed said.

The pause in the fighting will last about a week until the end of the Muslim holy month of Ramadan and aims to allow the delivery of assistance to some of the 21 million Yemenis in need.

The U.N. has worked intensively to broker a ceasefire to halt more than three months of many-sided fighting inside the country and Saudi-led air strikes against the Houthis and their army allies that have killed more than 3,000 people.

“For the humanitarian pause, we are going to start tomorrow evening and we have assurances from all the parties, and we are quite optimistic it will be respected,” Ould Cheikh Ahmed said.

“We have agreed to go ahead, based on two major points. The first is the commitment of all parties not to violate this ceasefire, this humanitarian pause. The second is that humanitarian assistance can reach all parts of Yemen,” he added.

Relief agencies say the fighting and a near-blockade imposed by an alliance of Arab states, aimed at stopping weapons deliveries to the Houthis, have caused a humanitarian disaster in Yemen, with over 80 percent of its 25 million people now needing some form of emergency aid.

Rights groups have also condemned local blockades by armed groups on supplies headed for war-torn civilian areas.

The United States fears the turmoil will strengthen Al-Qaeda in the Arabian Peninsula, the deadliest branch of the global militant group.

AQAP’s new leader Qassim al-Raymi, appointed after his predecessor was killed in U.S. drone strike last month, called for attacks on the United States in a taped speech released on Thursday.