Yemeni security officials say U.N. envoy Martin Griffiths has arrived in the capital, Sanaa, to discuss the situation in and around the key port city of Hodeida.

The officials say Griffiths is meeting Tuesday with Houthi rebel leader Abdul-Malek al-Houthi to discuss the implementation of peace deals from December talks with Yemen's internationally recognized government.

The U.N. said earlier this month that Yemen's warring sides have agreed on the first stage of a mutual pullout of forces from Hodeida.

Both sides agreed to a cease-fire in December, as well as a prisoner exchange that has yet to take place.

Yemen has been embroiled in a stalemated war pitting a Saudi-led coalition against Iran-backed rebels, known as Houthis, since March 2015.

The officials spoke anonymously as they weren't authorized to brief journalists.