UN Special Envoy to Yemen Martin Griffiths arrived in Yemeni capital Sanaa on Tuesday to hold talks with the Houthi leadership to bolster a cease-fire deal.

Griffiths made no remarks to reporters upon his arrival.

His visit came a day after representatives from Yemen's Saudi-backed government and Houthi rebels winded up two-day talks on a UN ship off the Yemeni coast, during which "they agreed on a mechanism and new measures" to implement the deal, a UN statement said.

The visit also came after Griffiths met with Yemeni President Abd-Rabbu Mansour Hadi in Saudi Arabia's capital Riyadh.

"I am grateful to him and his government's commitment to the Stockholm Agreement and his personal support to find a political solution to the conflict in Yemen," Griffiths wrote on Twitter on Monday.

The deal was reached in Stockholm in December last year and focused on enforcing cease-fire and mutual troops withdrawal from Hodeidah port city as the first phase toward a comprehensive political solution.

Hodeidah is the key lifeline entry of most Yemen's commercial imports and humanitarian aid.

More than four years of grinding war in Yemen has pushed over 20 million people to the verge of starvation.