DUBAI/ADEN (Reuters) - Representatives from both sides in the Yemen conflict met on a ship on the Red Sea on Sunday in a U.N.-led push to implement a stalled troop withdrawal from Yemen’s main port of Hodeidah as agreed at December peace talks, a U.N. official told Reuters.

Slideshow ( 4 images )

The United Nations is overseeing the implementation of a ceasefire and troop withdrawal accord in Hodeidah, the main entry point for most of Yemen’s imports, in the hope it will lead to a political solution to the almost four-year war.

The warring parties were meant to withdraw their forces by Jan. 7 as part of efforts to avert a full-scale assault on Hodeidah, but have failed to do so as the Iranian-aligned Houthi group and the Saudi-backed government disagree on who should control the city and ports.

Sunday’s meeting was the third time the U.N.-led Redeployment Coordination Committee (RCC) convened since it was formed in December, bringing together the Houthis with the Saudi-backed, internationally recognized Yemeni government and U.N. mediators.

The parties met on a U.N. ship because attempts to convene the third meeting in territory held by coalition forces failed because the Houthis were unwilling to cross the frontline, sources have told Reuters. The first two meetings were held in territory under Houthi control, after which the head of the U.N. mission tasked with overseeing the deal, Patrick Cammaert, shuttled between the two parties.

The vessel picked up a delegation from Yemen’s internationally recognized government at an offshore meeting point in the Red Sea before sailing to Hodeidah to pick up the Houthi delegation, a U.N. statement said on Saturday.

The spokesman for the Yemeni government’s delegation to the RCC, Sadiq Dweid, told Reuters the committee had discussed Cammaert’s proposals for the troop withdrawal at Sunday’s meeting.

“The meetings will continue,” he said.

The truce has largely held in Hodeidah, but clashes have increased in recent weeks and the U.N. Yemen Envoy Martin Griffiths has urged all parties to reduce tensions. Violence has continued in other parts of the country not subject to the deal.

Griffiths’ office told Reuters the meeting had begun on Sunday.

The conflict, widely seen in the region as a proxy war between Saudi Arabia and Iran, has been bogged down in military stalemate for years.

A Sunni Muslim Arab coalition led by Saudi Arabia and the United Arab Emirates intervened in Yemen in 2015 to try to restore the government of Abd-Rabbu Mansour Hadi after it was ousted from power in the capital Sanaa by the Houthis in late 2014.

The Houthis, who say they are enacting a revolution against corruption, control most urban centers in the poorest Arabian Peninsula nation while Hadi’s government controls the southern port of Aden and string of coastal towns.

Pope Francis said on Sunday he is following the humanitarian crisis in Yemen with great worry and urged all sides to respect international agreements and ensure food reaches suffering Yemenis.