Yemen's government and the Houthi rebels have agreed on the first stage of a mutual pullout of forces from the port city of Hodeida, a key entry point for humanitarian aid, the United Nations said.
The agreement came after two days of meetings in Hodeida, a UN statement said.
The warring parties agreed to a ceasefire in the city and a prisoner exchange during talks held in Sweden in December, but the implementation of both has been stalled.
The statement said both sides "made important progress on planning for the redeployment of forces as envisaged in the Hodeida agreement".
Yemen's government has been battling the rebels since 2014, when the Houthis swept down from the north and seized the capital Sanaa.
A Saudi-led coalition entered the war on the side of the government in March 2015.
The stalemated conflict has killed tens of thousands of people and raised fears of famine.
"It's encouraging news that this has happened, as people had been losing faith in the process, causing fears that we'd soon see a return to combat in and around Hodeida," said Peter Salisbury, a senior analyst at the Brussels-based International Crisis Group.
He said the parties now need to implement the agreement, warning that "there is plenty of room for them to play games here, so we shouldn't get overexcited".
British Foreign Secretary Jeremy Hunt hailed their progress, tweeting that the agreement must be "swiftly finalised & implemented" and urging progress on the prisoner release.
Under the UN-brokered agreement reached in December, both sides agreed on the redeployment of forces out of Hodeida, which is currently controlled by the Houthis.
Local authorities and police would run the city and its three ports under UN supervision.
The first stage of implementation, agreed upon over the weekend, would see both sides withdraw forces from the ports of Hodeida, Salif and Ras Issa, which handle about 70% of Yemen's imports.
UN envoy Martin Griffiths, meanwhile, departed from Sanaa on Monday, a day after meeting with rebel leader Abdul-Malek al-Houthi to discuss the "complex situation" in and around Hodeida.