UNITED NATIONS, Feb. 7 (Xinhua) -- UN Under-Secretary-General for Humanitarian Affairs Mark Lowcock on Thursday asked the Houthi rebels in Yemen to grant urgent access to a major food storage site.

"I am deeply concerned that the United Nations has been unable to access the Red Sea Mills in Hodeidah since September 2018," said Lowcock in a statement. "Access to the mills grows ever more urgent as time passes and the risk of spoilage to the remaining grain increases."

Enough grain to feed 3.7 million people for a month has sat unused and possibly spoiling in silos at the mills for more than four months, while nearly 10 million people across the country remain just a step away from famine, noted Lowcock, who is also the world body's emergency relief coordinator.

"No one gains anything from this. But millions of starving people suffer."

To date, Houthi forces have declined to authorize the United Nations to cross front lines into government-controlled areas to access the mills, citing security concerns, said Lowcock. "Discussions continue with all parties, and I appreciate the genuine efforts that have been made on all sides to find a solution. But it remains elusive."

He asked all parties, in particular, the Houthis, to finalize an agreement and facilitate access to the mills "in the coming days."

Last month, two silos were hit by mortar shells landing in the compound of the mills. The resultant fire destroyed some of the grain -- probably enough to feed hundreds of thousands of people for a month, he noted.

The United Nations and its humanitarian partners are scaling up to reach 12 million people with emergency food assistance, which is a 50 percent increase over 2018 targets. In December, the World Food Programme reached more than 10 million people, a record achievement, said Lowcock.

"We can save huge numbers of people, most of them in areas controlled by Ansar Allah (Houthi rebels). But we need more help to do that from the authorities who control these areas."

An almost four-year-old war between Houthi rebels and forces loyal to the government of Abdrabbuh Mansur Hadi has brought the country to the brink of famine.