Yemeni government, Houthis set up joint positions in Hodeida
The world body's envoy for Yemen, Martin Griffiths, wrote on Twitter that the establishment of the four positions along frontlines in the key port city, and the deployment of liason officers, were positive moves.
"This step forward will enhance de-escalation in flashpoint areas and save lives," he wrote on Twitter.
The Saudi-backed government of President Abed Rabbo Mansour Hadi and the Iran-aligned Houthi rebels have been embroiled in a devastating conflict since 2014.
Last year, Hadi loyalists backed by a Saudi-led military coalition launched an offensive to retake the Red Sea port city, which serves as a crucial entry point for imports and humanitarian aid.
UN-brokered talks in December 2018 between the warring parties in Sweden yielded a series of breakthroughs including a ceasefire in Hodeida, where combat largely ceased.
In May 2019, the UN announced that the rebels had withdrawn from Hodeida and two other nearby ports, the first practical step on the ground since the truce deal.
UN observation mission chief Abhijit Guha also welcomed the establishment of joint observation posts, "designed to facilitate direct inter-party de-escalation in flashpoint areas seen as susceptible to conflict", according to a UN statement.
A government official, who requested anonymity, told AFP the observation points had been working "smoothly".
A Saudi-led coalition intervened in Yemen in March 2015 to bolster the government after the rebels took over the capital of Sanaa.
The conflict has since killed tens of thousands of people - most of them civilians - and driven millions more to the brink of famine, in what the UN calls the world's worst humanitarian crisis.