UNITED NATIONS, Feb. 26 (Xinhua) -- Representatives of the UN food agency briefly visited the Red Sea mills of Yemen on Tuesday but were unable to determine if the wheat in storage was all fit for feeding starving Yemenis, a UN spokesman said.

"A team from the World Food Program (WFP) visited the Red Sea mills," said Stephane Dujarric, spokesman for the UN secretary-general. "This visit was the first by WFP to these vital wheat stores since September of 2018."

The WFP has been appealing for access to the mills for the past few months. Access was cut off by fighting in the area in Hodeidah, home to the crucial mills and as a key port handling some 70 percent of imports into Yemen.

"WFP is hopeful that Tuesday's brief visit will pave the way for more sustained access, allowing it to carry out a full assessment of the conditions of the wheat and the milling facilities themselves," Dujarric said.

While the mills hold enough wheat to feed 3.7 million people for at least a month, the spokesman said, adding that the WFP is unable to confirm how much of it is still fit for human consumption.

He said the agency has been using other in-country wheat stocks as well as importing more wheat, both by sea and overland from Oman, to cover food needs for nearly 10 million people in Yemen.

Also on Tuesday, a pledging conference for Yemen humanitarian aid in Geneva raised donation assurances of 2.6 billion U.S. dollars, up from 2 billion dollars in 2018.

Most of the increase over the 2018 pledges came from Saudi Arabia and the United Arab Emirates, said UN Secretary-General Antonio Guterres, who chaired the conference.

The long-running Yemeni conflict has caused the world's worst humanitarian crisis. Currently, some 24 million Yemenis, or 80 percent of the entire population, need humanitarian aid and protection, with some 20 million requiring help to secure food, the United Nations has said.