ASHINGTON, Dec. 21 - In one of the first signs of the effects of the ever tightening federal budget, in the past two months the Bush administration has reduced its contributions to global food aid programs aimed at helping millions of people climb out of poverty.

With the budget deficit growing and President Bush promising to reduce spending, the administration has told representatives of several charities that it was unable to honor some earlier promises and would have money to pay for food only in emergency crises like that in Darfur, in western Sudan. The cutbacks, estimated by some charities at up to $100 million, come at a time when the number of hungry in the world is rising for the first time in years and all food programs are being stretched.

As a result, Save the Children, Catholic Relief Services and other charities have suspended or eliminated programs that were intended to help the poor feed themselves through improvements in farming, education and health.

"We have between five and seven million people who have been affected by these cuts," said Lisa Kuennen, a food aid expert at Catholic Relief Services. "We had approval for all of these programs, often a year in advance. We hired staff, signed agreements with governments and with local partners, and now we have had to delay everything."

Ms. Kuennen said Catholic Relief Services had to cut back programs in Indonesia, Malawi and Madagascar, among other countries.

Officials of several charities, some Republican members of Congress and some administration officials say the food aid budget for the fiscal year that began Oct. 1 was at least $600 million less than what charities and aid agencies would need to carry out current programs.

"We are all at a crossroads, struggling with the budgetary crunch, but the problem is, there isn't enough to go around," said Ina Schonberg, director of food security programs for Save the Children. She said the cutbacks had had the biggest effect for her agency in Tajikistan and Nicaragua.

Ellen Levinson, head of the Food Aid Coalition, said the best estimate for the amount of food that was not delivered in November and December was "at least $100 million."

The administration attributed the recent cutbacks to the huge demands from food crises this year, especially in Africa, and the long delay in approving a budget.

Chad Kolton, spokesman for the Office of Management and Budget, said the administration "acknowledged the need for additional resources" in food aid, but said there was no way he could say whether more programs would be cut in the coming year. "The vast majority of resources available is going to emergency food aid," he said.

For the other programs that have been cut back, he said, "We are going to look at a couple of different things, such as the importance of the program and whether it is able to produce results."

One administration official involved in food aid voiced concern that putting such a high priority on emergency help might be short-sighted. The best way to avoid future famines is to help poor countries become self-sufficient with cash and food aid now, said the official, who asked not to be identified because of the continuing debate on the issue. "The fact is, the development programs are being shortchanged, and I'm not sure the administration is going to make up the money," the official said.

At a private meeting with charities last month, Lauren Landis, the director of the Food for Peace program at the Agency for International Development, warned that her budget for food aid was smaller than in recent years and that the increased costs of buying and shipping commodities presented "a significant challenge," according to the minutes of the meeting. She also warned that the Office of Management and Budget had been pressing her office "to reduce its spending on development programs, and this has been a consistent message over the past year."

Several Republican and Democratic members of Congress are joining with food aid advocates to convince the administration that food aid should not be cut.

Last month, Representative Jo Ann Emerson, Republican of Missouri, led an effort with more than 30 other legislators that persuaded the administration to release 200,000 tons of grain from a trust fund for emergency food aid to Sudan.

Now she is lobbying the administration to finance foreign food aid programs fully and, if possible, increase the money. "I'm not saying the president is opposed to this, but we haven't had any indication what will happen," said Ms. Emerson, who emphasized that hers was a bipartisan effort.

She also said Europe should increase its food aid and relieve some of the pressure on the United States, which is by far the largest donor to United Nations food programs, contributing almost half of the total.

Further complicating aid programs is a debate at the World Trade Organization over concerns that the United States has used food aid to dump surplus commodities in foreign countries where the supply has undercut local farmers' earnings.