The White House may soon propose the biggest change in US food aid since the programmes were created during the Cold War - donating cash for hunger relief instead of shipping American-grown food to global trouble spots, say farm groups and charities.

Reformers have argued for years that cash donations, the method used by most nations, are more efficient and speedier. But food donation has been the favored US approach since the Food for Peace program was enacted in 1954.

Groups on both sides of the issue said on Monday that the Obama administration, when it unveils its budget for the fiscal year opening October 1, may endorse cash donations and propose fewer food donations.

"This is a very serious proposal," said Eric Munoz of Oxfam, the international development group. "We think the intent is there" for reform.

Oxfam and allies such as American Jewish World Service point to a 2012 Cornell University study as support for the idea that cash, used to buy local food near the recipients' area, is more efficient than sending bags of flour or rice, bottles of vegetable oil, dried milk and other aid.

The study said local purchase "can often afford valuable cost and times savings," as much as 50 per cent in the cost of grain. Processed foods sometimes cost more locally or offered smaller savings.

As a rule, at least 75 per cent of all US food aid must travel on US-flagged vessels, which also drives up the cost.

The White House and US Agriculture Department declined to comment to Reuters about a possible cash proposal.

Farm groups and agribusinesses said they opposed dramatic cuts or the elimination of Food for Peace.

Steep cuts will undermine "one of our most effective, lowest-cost national security tools" that builds good will overseas, they said in a letter last week to senators who oversee food aid programmes.

The United States is the world's largest food aid donor, providing nearly $2 billion a year in aid. Food for Peace, devoted to hunger relief and local food security, is the largest of the aid programmes with $1.47 billion in funding this year.

Food donation also has strong support on Capitol Hill. The chairwomen of the Senate Appropriations and Agriculture committees were among the 21 signers of a February 20 letter calling for continued funding of Food for Peace.

The letter, first reported by The Hagstrom Report, an agricultural newsletter, opened the public scuffle over cash donation vs food donation.

Food aid groups planned to circulate on Tuesday a statement calling for the White House to support "bold reform" that includes local purchase of food and an end to the practice known as monetisation. In it, the United States gives food to groups that sell it so they can operate programmes to help poor people in targeted nations. - Reuters