The UN envoy for Yemen arrived in the capital Sanaa on Sunday, just days after the Yemeni warring parties built joint cease-fire observation sites in the country's lifeline port city of Hodeidah.

Martin Griffiths is set to hold talks with Houthi rebel leaders to push forward to fully implement the deal, Houthi-run al-Masirah TV reported.

Griffiths arrived from the Saudi capital Riyadh, where he had met Yemeni government officials over the past two days.

His visit to the rebel-held capital came as the cease-fire in Hodeidah was largely holding despite intermittent skirmishes with both sides blaming each other.

Last week, representatives of the government and its foe Houthi rebel group established joint cease-fire observation posts and deployed liaison officers along the Hodeidah city frontlines.

Abhijit Guha, head of the UN cease-fire monitoring mission in Hodeidah, has observed this process on the ground over the past week.

The process came in accordance with a UN-sponsored cease-fire agreement reached in Stockholm in December 2018.

Iran-allied Houthi rebels control much of Hodeidah while the Saudi-backed government troops have advanced to the southeastern districts.

The war of more than four years has killed tens of thousands of people, displaced 3 million and pushed over 20 million Yemenis to the verge of starvation, according to the UN.

The 2018 Stockholm Agreement was seen as the first phase toward achieving a comprehensive political solution to end Yemen's civil war.