Martin Griffiths told the UN Security Council on Monday that agreement for the first phase of withdrawals was reached after negotiations between the warring parties and Danish General Michael Lollesgaard, who heads the UN operation monitoring the ceasefire and a redeployment agreement reached in Sweden in December 2018.
"Both parties have now accepted a detailed redeployment plan," Griffiths said via video conference from the Jordanian capital, Amman, Presstv Reported.
He said he had received assurances from the leader of Ansarullah, Abdul-Malik al-Houthi, when they met in Sana’a last week that Houthi forces would support the deal.
"Let us be clear that when, and I hope it is when and not if, these redeployments happen, they will be the first voluntary withdrawal of forces in this long conflict," Griffiths said.
Elsewhere in his remarks, the UN official said he was laying the groundwork for broader negotiations on ending the deadly campaign led by the regime in Riyadh against Yemen. "We all need to see tangible progress in Hudaydah before moving to focus on the political solution."
The UN announced a deal on a two-stage pullback from Hudaydah and its ports on February 17, but the redeployment failed to materialize on the ground.
The redeployment of forces is a critical part of a truce reached during UN-mediated peace talks in Sweden.
The Houthis have repeatedly complained that the Saudi-led coalition has been violating the ceasefire. UN diplomats earlier said the Houthis refused to pull away from Hudaydah ports as part of the first stage, citing fears that forces linked to the Saudis will move in to take over facilities there.
Saudi Arabia and the United Arab Emirates launched the Hudaydah offensive in June 2018 but have been facing strong resistance from Yemeni armed forces, led by the Houthis, as well as the city’s residents.
Hudaydah, a lifeline for millions of Yemenis, has seen some of the heaviest fighting in the Saudi-led war, which Riyadh began in March 2015.
The imposed war initially consisted of an aerial campaign but was later compounded by a naval blockade and the deployment of mercenaries to Yemen.
Yemen is going through the worst humanitarian crisis since 2015.
Efforts to crush Houthis and reinstate Riyadh ally and former President Abd Rabbuh Mansur Hadi have so far failed, forcing Saudi Arabia to push for peace with the Yemeni resistance movement and its allies in the army.