A revived effort to end Yemen’s war under the administration of US President Joe Biden appeared to lead to nowhere on Wednesday when the UN’s envoy to the country said peace talks had hit a roadblock.

The UN Envoy to Yemen, Martin Griffiths, said that a week-long round of talks in Saudi Arabia and Oman involving Biden’s envoy to Yemen, Tim Lenderking, had failed to make progress, as a Houthi offensive on the government-held city of Marib has not stopped.

“We have been discussing these issues for over a year now,” Griffiths said.

He added, “The international community has been supporting us in full force. Unfortunately, we are not where we would like to be in reaching a deal. Meanwhile, the war has continued unabated, causing immense suffering to the civilian population.”

Since taking office in January, the Biden administration has sought to end Yemen’s conflict by withdrawing support for offensive operations by the Saudi-led coalition that is battling Yemen’s Iran-aligned Houthis.

Saudi Arabia announced a peace plan in March, which the Kingdom believed that plan would lift the blockades and pave the way for a ceasefire between the Saudi-backed government and the Houthis, who control the capital Sanaa and much of the north.

This week’s negotiations involving Griffiths and Lenderking were aimed at advancing that ceasefire, but are understood to have been complicated by the Houthi assault on gas-rich Marib, the government’s last northern stronghold.

“I will keep engaging the parties to the conflict and all involved and concerned actors and stakeholders to offer them opportunities to find common grounds to help advance the peace efforts,” said Griffiths.

The Saudi-led military coalition intervened in Yemen in 2015 after the Houthis ousted the government from Sanaa.

The war has created what the US calls the world's worst humanitarian crisis, with some 80 per cent of the country’s population of 29 million needing aid and 13 million facing starvation.

-Agencies