UN aid chief Mark Lowcock warned Saturday that Yemen was "on the brink of a major catastrophe", as the world body pushes for peace talks in the impoverished and war-wracked country.
His comments came after renewed deadly clashes between Huthi rebels and pro-government forces in the Red Sea port city of Hodeida, which is vital for the flow of humanitarian aid.
"Yemen is on the brink of a major catastrophe," Lowcock said, as he wrapped up a visit to the country.
He said conditions had deteriorated alarmingly since his last visit in October 2017 to Yemen, which the United Nations has termed the world's worst humanitarian crisis.
"In Aden, I met emaciated children so malnourished they could barely open their eyes," Lowcock said in a statement.
"Humanitarian assistance helps many of these children recover. But I also heard heartbreaking stories of children relapsing again and again because their families simply can't afford food or proper medical care," he said.
Lowcock reiterated the UN's readiness to help ensure that the rebel-held Hodeida port, a key entry point for imports and aid, can remain open.
Under heavy international pressure, Saudi-backed pro-government forces have largely suspended an offensive launched in June to take the port city.
Sporadic fighting has however continued since a fragile truce began on November 13.
- Peace talks face 'setbacks' -
Clashes on Friday in the east and south of Hodeida left 10 fighters dead, an official and medical sources told AFP on Saturday.
Medical sources confirmed the bodies of eight rebels had been transferred to hospitals, and that two fighters with pro-government forces were also killed.
Intermittent clashes continued on Saturday, Hodeida residents told AFP by phone.
Saudi Arabia accused the Huthis of launching a "military projectile" across the border Friday, saying it hit a house and injured two people in the kingdom, the official SPA news agency reported.
The violence follows a visit to Hodeida last month by UN envoy Martin Griffiths to press for talks.
The proposed peace talks have been backed by both the rebels and the Saudi-led government and were expected to take place in Sweden next week.
UN Secretary-General Antonio Guterres, however, has played down the early December schedule and said he hoped talks would start "this year".
"But, as you know, there have been some setbacks," he said on Thursday.
Previous talks planned for September in Geneva failed to get underway as the Huthi delegation never left Yemen's rebel-held capital Sanaa, arguing that the United Nations could not guarantee their safe return.
Lowcock said it was "not too late" to pull back Yemen from the brink but warned that more resources were needed.
"Yemen is the world's largest humanitarian operation, but in 2019 it will need to be substantially bigger," he said.
Donors this year have provided $2.3 billion (two billion euros) for the 2018 response plan, or about 80 per cent of requirements, he added.
The latest warnings come as President Donald Trump's administration faces mounting pressure over its backing for the Saudi-led military campaign, with the US Senate on Wednesday voting to consider a resolution that would end this support.
The murder of journalist Jamal Khashoggi in Saudi Arabia's consulate in Istanbul on October 2 has shone a harsh spotlight on the kingdom.
Secretary of State Mike Pompeo acknowledged the humanitarian crisis in Yemen had reached "epic proportions", but insisted that US backing for Riyadh's actions would continue.
"The programme that we're involved in today we intend to continue," Pompeo told CNN Saturday when asked about military assistance to the Saudi-led coalition.
According to UN figures, nearly 10,000 people have been killed since the Saudi-led coalition joined the conflict in 2015 to bolster the government against Huthi rebels.
UN agencies say that 14 million people are at risk of starvation in Yemen.