WASHINGTON - The US Agriculture Department on Monday released bleak figures on the state of hunger in the United States, showing that more American families are having difficulty feeding their members.

The annual Household Food Security report showed that in 2008, families in 17 million households - 14.6 per cent of US homes - had difficulty putting enough food on the table at some point during the year, an 11 percent increase over 2007.

The figures "represent the highest level observed since nationally representative food security surveys were initiated in 1995," the USDA said.

"The fundamental cause of food insecurity and hunger in the United States is poverty - marked by a lack of adequate resources to address basic needs such as food, shelter and health care," the statement added.

President Barack Obama described as "unsettling" the report which came as some 60 heads of state and government were attending the World Summit on Food Security in Rome.

"This trend was already painfully clear in many communities across our nation, where food stamp applications are surging and food pantry shelves are emptying," Obama said.

The president said he was especially troubled that there were more than 500,000 US families "in which a child experienced hunger multiple times over the course of the year.

"Our children's ability to grow, learn, and meet their full potential - and therefore our future competitiveness as a nation - depends on regular access to healthy meals," he said.

The first task to reverse the trend of rising hunger "is to restore job growth, which will help relieve the economic pressures that make it difficult for parents to put a square meal on the table each day," Obama said.

The president also said his administration has increased help for low-income families seeking food assistance, especially those with children.