The UN special envoy for Yemen will travel to the rebel-held capital of Sanaa on Saturday for talks with Houthi leaders after reports of repeated violations of a landmark truce in Hodeidah by the Iran-backed insurgents.
Martin Griffiths will also meet the head of the UN ceasefire monitors, retired Dutch general Patrick Cammaert, in Sanaa, said UN spokesman Farhan Haq.
The truce agreed at peace talks in Sweden last month was holding, Mr Haq said, despite the more than 250 rebel violations complaints reported to the Security Council by the Yemeni, UAE and Saudi representatives to the UN.
"The cessation of hostilities in Hodeidah continues to hold," Mr Haq said on Thursday.
He said Mr Griffiths would also travel to Saudi Arabia to meet Yemen's President Abdrabu Mansur Hadi and other officials in Riyadh.
The council is expected to hear a report from Mr Griffiths next week, but no firm date has been decided for that meeting.
The United Nations hopes to bring the sides together again later this month, possibly in Kuwait, to follow up on the progress made in talks in Stockholm in December, diplomats said.
Under the deal reached in Sweden, the rebels agreed to redeploy from Hodeidah, the Red Sea port city that is the entry point for food aid to millions of Yemenis on the brink of famine.
However, the UAE, Saudi Arabia and Yemen complained to the Security Council this week that the rebels were failing to comply with the ceasefire, which requires them to withdraw fighters from three ports in Hodeidah before armed forces from both sides completely pull out of the city and the surrounding area.
The rebels launched 268 attacks between December 18, when the ceasefire went into effect, and December 30, and appeared to be fortifying their positions in the city instead of preparing to withdraw, the three countries said in a letter submitted on December 31.
There have been further Houthi attacks since then, while relations between the rebels and Mr Cammaert, who chairs the joint Redeployment Co-ordination Committee for overseeing the withdrawal, have grown increasingly strained, sources in Hodeidah told The National.
"One of the Houthi representatives in the RCC accused Gen Cammaraet of being biased towards the government, and threatened to call their loyalists in Hodeidah on to the streets to protest against him and to ask him and the RCC to leave the city as soon as possible," said Col Waddah Al Dubeish, a spokesman for the pro-government Amalikah Brigades.
"The day before that, the Houthi-appointed acting governor of Hodeidah, Mohmed Ayesh Quhaim, held a meeting with the general secretaries of the 13 districts in Hodeidah and forced them to sign a letter condemning Gen Cammaert and accusing him of being biased towards the government," he said.
The rebels also shelled civilian areas in the southern Hodeidah district of Hays on Thursday night, residents said, destroying the home of a blind elderly couple the village of Al Maghfal.
"We went to rescue them when we saw the smoke rising from their house," a resident of the village told The National. "We found them partially covered by rubble and took them to the health centre for treatment."
The rebels also fired rocket-propelled grenades and mortars at the homes of residents they accused of cooperating with pro-government forces.
The war between the Houthis and troops loyal to Mr Hadi escalated in March 2015, when he was forced to flee into exile in Saudi Arabia and the Saudi-led coalition intervened.
The conflict has unleashed in Yemen what the United Nations has described as the world's worst humanitarian crisis.