President George W. Bush called on Congress Thursday to approve $770 million to help alleviate dramatically escalating food prices that threaten widespread hunger and increasing social unrest around the world.

In a surprise appearance at the White House, Bush announced he is asking lawmakers to approve the additional funds for global food aid and development programs. The money is being included in a broader $70 billion Iraq war funding measure for 2009 that the White House sent to Capitol Hill on Thursday.

"In some of the world's poorest nations, rising prices can mean the difference between getting a daily meal and going without food," Bush said. "The American people are generous people and they're a compassionate people. We believe in the timeless truth `to whom much is given, much is expected."'

The new money comes on top of $200 million Bush ordered released two weeks ago for emergency food aid. Even so, Bush called it "just the beginning" of the U.S. effort to help. He said the United States would spend a total of $5 billion this year and next on food aid and related programs.

"America's in the lead, we'll stay in the lead and we expect others to participate along with us," he said.

The new funds are aimed at meeting immediate needs with direct shipments of food aid, and the White House said the amount would allow for millions more people to get help,

But the funds also have long-term aims, boosting U.S. programs to help farmers in developing countries increase productivity and making cash payments to purchase local crops, so communities are less in need of emergency help in the first place.

The issue has become more urgent recently because of food shortages and rising prices that, combined with high gas costs and rising home foreclosures in the US, are putting a huge squeeze on families at home and abroad. What has been termed the first global food crisis since World War II has resulted in cries for help from United Nations officials and raised questions about how Bush will respond.

Some have blamed the food crisis in part on Bush-backed policies that push food-based biofuels such as ethanol as alternative energy sources. Bush says diverting corn and soybeans into fuel is still a smart approach, though he favors increasing funding for research into eventually using waste byproducts of those commodities rather than the edible portion.

The United States is the world's largest provider of food aid, delivering more than $2.1 billion to 78 developing countries last year.