SANAA, June 16 (Xinhua) -- The UN special envoy to Yemen Martin Griffiths arrived in Yemen's Houthi-held capital Sanaa on Saturday in renewed effort to stop the fighting in Hodeidah, the rebel-controlled Saba news agency reported.

It is the second official visit to Sanaa by Griffiths in two weeks.

Griffiths stressed that the UN is determined to press ahead with the political process to halt the ongoing fighting in the southern port city of Hodeidah.

The coalition forces, led by Saudi Arabia and United Arab Emirates, seized control of the Hodeidah airport on Saturday.

The major assault began on Wednesday in a bid to block the only sea port to the north and bring the Iranian-allied Shiite Houthi rebels into their knees.

International humanitarian agencies have warned that an assault on Hodeidah would be a major disaster to the densely populated port city and would block aid supplies to more than 20 million people.

On June 4, Griffiths met Houthi top official Mahdi al-Mashat, president of Houthi Supreme Political Council, to discuss possibilities of returning to the negotiation table with the government of exiled President Abd-Rabbu Mansour Hadi.

Al-Mashat told Griffiths that "respecting sovereignty and independence of countries should be a starting point for any political process and negotiations in Yemen."

Hodeidah is the only lifeline route of supplying imports and humanitarian aid to the northern Yemen, which is under control of the Iranian-allied Houthis.

The Saudi-led coalition intervened in Yemen in March 2015 to roll back the Houthi rebels' gains and restore Hadi's rule.

The war has killed over 10,000 people, mostly civilians, and forced 3 million others out of their homes.