War in Yemen is 'back in full force,' says UN mediator

The war in Yemen is "back in full force," the United Nations mediator told the Security Council on Tuesday amid renewed attempts to get the warring parties to talk and UN warnings that the country is spiralling toward a massive famine.

Martin Griffiths told the council that there had been a dramatic deterioration in the more than six-year-long war with a Houthi offensive on Marib - the Yemeni government's last northern stronghold - putting millions of civilians at risk.

"We are also seeing other fronts in Yemen opening, including with military escalations in Hajjah and Taiz and Hudaydah. The war is back in full force," he told the 15-member council.

A Saudi Arabia-led military coalition intervened in Yemen in 2015 after the Iran-aligned Houthi group ousted the country's government from the capital Sanaa. The Houthis say they are fighting a corrupt system.

US President Joe Biden has made ending the war in Yemen a priority. His special envoy Tim Lenderking said on Friday that a "sound plan" for a ceasefire in Yemen had been before the Houthi leadership for "a number of days".

"The death and violence must stop. We call on the Houthis to accept an immediate, comprehensive, nationwide ceasefire and to cease all attacks. In the meantime, we will continue to hold Houthi leadership to account," US Ambassador to the United Nations Linda Thomas-Greenfield told the council.

The United Nations describes Yemen as the world's worst humanitarian crisis. Some 80% of Yemenis need help, with 400,000 children under the age of 5 severely malnourished, according to UN data. For much of its food, the country relies on imports that have been disrupted over the years by all warring parties.

"A nationwide ceasefire, along with the opening of Sanaa airport and ensuring the unhindered flow of fuel and other commodities into Yemen through Hodeidah ports, are urgent humanitarian imperatives," Griffiths said.