The Yemeni city of Hodeida, home to both a valuable port and frontlines, has proved the most complex issue at UN-sponsored peace talks between warring parties, a source said.

Yemen's Huthi rebels seized the Red Sea city of Hodeida, a traditional conduit for 90 percent of food imports to impoverished Yemen, in a massive territorial takeover in 2014, sparking the intervention of Saudi Arabia and its allies on behalf of the government the following year.

Shipments to Hodeida, including humanitarian aid, have been severely restricted by the coalition. Huthi fighters who are now ensconced in residential neighbourhoods to fight government forces.

The government demands the rebels withdraw completely from the city. The Huthis have refused.

"Hodeida is the most difficult of all," a UN source said, adding that progress on the port was crucial to finding a solution to the conflict.

The Saudi-led alliance launched an offensive to retake densely-populated Hodeida in June, sparking fears of a fresh humanitarian crisis in a country already at the brink of famine.

Foreign Minister Khaled al-Yamani told AFP Saturday a full rebel withdrawal from Hodeida city and port were non-negotiable to the Yemeni government.

Yamani said the government was "ready to coordinate with the UN on supervision and the reinforcement of port operations" on condition the Huthis vacated the area.

The conflict has triggered what the UN calls the world's worst humanitarian crisis, with 14 million people now on the brink of .amine. Nearly 10,000 people have died in under four years, according to conservative estimates.

The Sweden talks, which opened Thursday, mark the first meeting between the Yemeni government and rival rebels since 2016 -- when more than three months of talks on ending the Yemen collapsed without a breakthrough.

Among the other issues under discussion in Sweden are potential humanitarian corridors, a prisoner swap and the reopening of the defunct Sanaa international airport.

AFP.