The UN envoy for Yemen, Martin Griffiths, urged rival Yemeni forces Monday to "bridge the gap" to reach a ceasefire, praising a diplomatic push for peace in the devastated country.

Yemen's civil war, which started in 2014, pits Iran-backed Houthi rebels against an internationally recognised government supported by a Saudi-led military coalition.

"Throughout the process we have suggested several ways to bridge the gap between the parties," Griffiths told reporters, speaking after meeting Houthi officials in the rebel-held capital Sanaa.

Yemen's long war has claimed tens of thousands of lives and displaced millions.

"There's an extraordinary amount of diplomatic consensus... there is a real diplomatic energy now, which hasn't always been the case," Griffiths said.

The effort to secure peace in Yemen comes after regional rivals Saudi Arabia and Iran restarted talks last month, their first high-level meeting since Riyadh cut diplomatic ties with Tehran in 2016.

While the United Nations and the US administration of President Joe Biden are pushing to end the grinding conflict, the rebels have demanded the re-opening of Sanaa airport before any ceasefire agreement.

The Saudi-led coalition imposed an air blockade on the Houthis, which has resulted in the closure of Sanaa airport to commercial flights since 2016.

"All of our proposals have also guaranteed the reopening of this airport where we are speaking today, Sanaa airport," said Griffiths,

Griffiths, a British diplomat, was earlier this month named as the UN's next humanitarian chief.