The United States has started delivering cash to Contra rebels inside Nicaragua to buy food, the State Department said Friday.

The money, which could total as much as $450,000 in the next month, is being delivered by the Agency for International Development in lieu of actual food, which has been blocked by the Nicaraguan government.The Sandinistas and the United States disagree as to whether food aid is permitted under an April 60-day truce between the Nicaraguan government and the rebels.

Congress authorized $47.5 million in non-lethal assistance to the Contras for the current fiscal year. At the time of the cease-fire there were an estimated 2,000 Contras inside Nicaragua and another 4,000 in Honduras. Administration officials estimated the amount per individual would run from the equivalent of 50 cents to $1 per to day.

State Department spokeswoman Phyllis Oakley said the rebels would be certain to spend the money on food rather than weapons because they have enough arms but are "desperately" in need of food.

She also said the rebels would have difficulty spending the cash, which is in the form of Nicaraguan cordobas, outside the country if they tried to purchase weapons.

The cash-for-food plan was proposed to Alan Woods, AID administrator, when the Sandinistas blocked the delivery of food to the Contras inside Nicaragua during the 60-day truce .

"Until the Nicaraguan government agrees to allow routine delivery of food, as called for in the Sapoa accord and expected by Congress, we must use other means of getting aid to the resistance inside Nicaragua," Wood said.