After raining tons of bombs on Yugoslavia in the last 2 1/2 months, NATO is considering a new mission for its planes: dropping food packages to hungry refugees hiding out in remote parts of Kosovo, U.S. officials said yesterday.

At the same time, a private relief operation funded by the U.S. government is gearing up to double its own airdrops out of concern that U.N. truck convoys may not be able to deliver food soon enough to save some of Kosovo's more malnourished internal refugees from starvation.

U.N. agencies plan to send in an initial truck convoy bearing 250 tons of food and other supplies as soon as NATO ground forces secure main roads, the U.N. High Commissioner for Refugees announced yesterday.

The aim of the air and land missions is to provide quick relief to an estimated 500,000 to 600,000 ethnic Albanians who have been driven from their homes by Serbian forces but have remained in Kosovo as "displaced persons." They are believed generally to be in much worse shape than the 800,000 people who have sought refuge in neighboring states.

In addition to food packages, NATO is being urged to drop thousands of leaflets over Kosovo warning people to refrain from rushing back to their homes until NATO forces have had a chance to clear mines, said Brian Atwood, administrator of the U.S. Agency for International Development.

AID wants the planes to deliver as many as a million "humanitarian daily rations" -- specially formulated high-protein versions of U.S. military meals -- within a few days. But the matter is still under discussion by NATO and U.S. military officers, AID officials said.

Meanwhile, the International Rescue Committee plans to step up the food drops it began May 30 with civilian planes and crews from Moldova, said Barbara Smith, a vice president of the private relief group. So far, the AID-funded operation has dropped 12 tons of food, persevering despite an early scare when its first flight came under antiaircraft fire over Kosovo.

The committee has been using two Russian-made Antonov 26 cargo planes to drop U.S. humanitarian daily rations and Swiss high-energy biscuits. A third plane from Moldova is due to join the operation at Pescara, Italy, by Monday, and Britain has offered to supply two C130 transport planes, with crews and support personnel, to boost the committee's airdrop capacity, said Hugh Parmer, an AID assistant administrator.

"We have established a very fragile lifeline for a small number of people, and we want to expand on it now," he said. "If trucks get there quickly, that's fine. But if they don't, we'll at least have some steady supplies of rations into those isolated areas."

For Kosovo's internally displaced, the peace agreement "has come just in time, because they couldn't have gone on much longer," Atwood said.