Ending Yemen's ongoing famine is the nation's "overarching humanitarian priority" amid a litany of crises, the UN’s outgoing special envoy for the country said on Monday.

Martin Griffiths told the UN Security Council that roughly two-thirds of Yemen's population – or about 20 million people – rely on humanitarian aid for their day-to-day needs. And roughly 5 million people "are one step away from succumbing to famine and the diseases that go with it," he warned.

An additional 10 million people "are right behind them," added Griffiths.

"Famine isn't just a food problem. It's a symptom of a much deeper collapse. In many ways, it is all of Yemen's problems rolled into one, and it demands a comprehensive response," he said.

Much of the country's starvation is tied to the extreme depreciation of Yemen's national currency and the collapse of the economy, with GDP plummeting 40% since 2015 when Houthi rebels seized control of the country.

The Yemeni rial, meanwhile, is trading at record lows to the dollar.

Khaled Mohamed Khiari, the UN's assistant secretary-general for the Middle East, raised further alarm over widespread fuel shortages that are acute and worsening in Houthi-controlled territories.

Only three ships carrying oil supplies were allowed to dock at Hudeydah Port since July, while four others remain in a holding area controlled by the Saudi-led anti-Houthi coalition, Khiari said.

All but one Yemen Petroleum gas station in Houthi-controlled territories have closed due to the shortages, and waiting times to refill gas canisters used for cooking have reached one month, according to the UN.

"We reiterate our call on the government of Yemen to urgently allow the entry of all essential commercial supplies, including fuel ships to Hudeydah without delay," said Khiari. "All parties must prioritize civilian needs, and abstain from weaponizing the economy, particularly in light of the critical humanitarian situation in the country."

Yemen has been beset by violence and chaos since 2014, when Iran-aligned Houthi rebels overran much of the country, including the capital Sanaa.

The crisis escalated in 2015 when the Saudi-led coalition launched a devastating air campaign aimed at rolling back Houthi territorial gains.

According to the UN Office for the Coordination of Humanitarian Affairs, the conflict in Yemen has so far claimed the lives of 233,000 people./aa