Yemen’s government and the rebel Houthi movement have agreed on the first phase of a withdrawal of forces around the key port of Hudaydah, the UN says.
A statement said the two sides had made “important progress on planning for the redeployment” following two days of talks, but no start date was given.
The pull-out is a critical part of a ceasefire agreed in Sweden in December.
Hudaydah is the principal lifeline for two-thirds of Yemen’s population, which is on the brink of famine.
The country has been devastated by a conflict that escalated in early 2015, when the Houthis forced President Abdrabbuh Mansour Hadi to flee abroad.
Alarmed by the rise of a group they saw as an Iranian proxy, Saudi Arabia and eight other Arab states intervened in an attempt to restore the government.
At least 6,800 civilians have been killed and 10,700 injured in the fighting, according to the UN. Thousands more civilians have died from preventable causes, including malnutrition, disease and poor health.
Under a deal brokered by the UN two months ago the warring parties agreed to withdraw from Hudaydah city and the ports of Hudaydah, Salif and Ras Issa, through which up to 80% of Yemen’s aid, fuel and commercial goods are delivered.
The first phase of the redeployment – from the ports and parts of Hudaydah city associated with humanitarian facilities – was meant to take place within two weeks.
But that deadline was missed amid disagreements over who would control the vacated locations and hundreds of alleged ceasefire violations.
Representatives of the government and Houthis attended talks over the weekend led by Lt Gen Michael Lollesgaard of Denmark, the head of the UN observer mission and chairman of the Redeployment Co-ordination Committee (RCC).
“After lengthy but constructive discussions facilitated by the RCC Chair, the parties reached an agreement on Phase 1 of the mutual redeployment of forces,” the UN said in a statement on Sunday night.
“The parties also agreed, in principle, on Phase 2 of the mutual redeployment, pending additional consultations within their respective leadership,” it added.
The second phase should see all remaining forces withdrawn from the region.
Last week, the UN appealed to both sides to give it access to a vast store of grain in Hudaydah port that holds enough food to feed 3.7 million people for a month.
Aid workers have not been able to reach the stores for five months, and the UN said the grain was now “at risk of rotting”.