UNITED NATIONS - Higher prices because of the conflict in Ukraine are contributing to unrest and insecurity in Yemen, challenging poorly funded aid efforts, UN humanitarians said on Wednesday.

The UN Office for the Coordination of Humanitarian Affairs (OCHA) said aid agencies remain concerned that the humanitarian crisis in Yemen will deteriorate sharply in the coming months due to economic problems, including a weaker currency and higher prices due to the Ukraine crisis.

"Unrest and insecurity are already mounting in some areas due to long-standing frustrations over currency depreciation, rising commodity prices, lack of services and jobs, decreasing aid and other issues," the office said. "We urge all donors to increase their contributions to the Yemen response plan right away to avoid further deterioration."

The UN humanitarian response plan for Yemen for 2022 is only 26 percent funded, it said.

OCHA said hunger is at the highest point since the escalation of the conflict two years ago, with more than 19 million people hungry, including more than 160,000 who are facing catastrophic conditions on the verge of famine.

The office said more than 8 million women and children in Yemen need nutrition assistance, including 538,000 severely malnourished children.

The UN Children's Fund said it might have to stop treatment for more than 50,000 severely malnourished children who will be at a much greater risk of death. The World Food Programme suspended nutrition assistance for 3 million moderately malnourished children and mothers.

Of the more than 4 million people internally displaced, families are four times more likely to experience food insecurity than the broader population. The UN Refugee Agency said that by July, it would reduce cash assistance, shelter and essential relief items for 150,000 displaced people across 18 governorates.