STATE DEPARTMENT — 

The United States "is working very hard" to have the cessation of hostilities remain in place after a fragile cease-fire in Yemen expired Monday.

“I think it's definitely something the Secretary [of State John Kerry] is still pursuing. And I would tell you that he had a conversation this morning with the deputy crown prince of Saudi Arabia as well as Foreign Minister [Adel] al-Jubeir about this issue," said State Department spokesman John Kirby on Monday.

A 48-hour cease-fire after nearly two years of war in Yemen expired at midday Monday and would not be renewed, according to a spokesman for a Saudi-led military coalition.

Kerry also spoke to United Nations Special Envoy for Yemen Ismail Ould Cheikh Ahmed on Monday.

The top U.S. diplomat is committed to a sustained cessation of hostilities in Yemen so that humanitarian aid can get to people and the political talks can resume, said the State Department.

The peace deal was announced unilaterally by the Saudi coalition but failed to halt fighting across the country between the Iran-aligned Houthis and Saudi-led forces, which intervened on the side of the exiled government in March 2015.

"The Houthi's have gained a commanding position on the ground, and they are not likely to negotiate away their gains. Given the sectarian issues at play, neither the Saudi-led coalition nor Iran is prepared to see its proxies defeated," American University's international peace and conflict resolution program director Hrach Gregorian told VOA.

The 20-month conflict has killed more than 10,000 people and displaced more than three million civilians.