The United States has provided 142 aircraft to other countries over the last decade for the interception and eradication of illegal drugs, the State Department said Wednesday.

More than half went to Mexico. "Facing growing violence from cocaine traffickers in their own countries, the governments of Latin America are fighting back," the department said. These countries are building rural mobile police units, eradicating coca plantations and looking for new crops for peasant growers, it said."The U.S. government is working with a number of Latin American governments to build up their own capabilities," a statement issued by the press office said. "We are committed to helping these governments and will continue to provide training and equipment."

Two years ago, Congress required that U.S. airplanes and helicopters used on anti-drug missions remain under U.S. ownership. The statement issued Wednesday was in response to inquiries prompted by an account by the Knight-Ridder News Service.

State Department officials said Tuesday that Bolivia had mounted machine guns on six U.S. helicopters under a drug-fighting contract with the Pentagon, while Peru and Guatemala have hired American civilian pilots. Americans are flying five helicopters in Peru and two aircraft to spray fields in Guatemala, the officials said.

The disclosure followed the Knight-Ridder story that said the State Department had amassed a force of 150 aircraft and planned to use U.S. civilian pilots to fly armed missions against drug traders in Latin America, the Caribbean and Asia.

Department spokeswoman Phyllis Oakley called the story an "exaggeration." She and Catherine Shaw of the department's International Narcotics Office then disclosed the Pentagon contract with Bolivia and the hiring of civilian pilots in Peru and Guatemala.

But Oakley said the 29 helicopters and planes acquired on order to combat drugs "are not for combat. They are not used for aggressive actions like bombing airstrips or cocaine laboratories. I am not aware of plans for their future use in that regard."

In all, 16 U.S. helicopters and planes are in South American countries to combat drugs, the officials said. But except for the six helicopters in Bolivia, none has weapons mounted aboard, Oakley said. She said, however, that local law enforcement agents may be carrying weapons aboard those aircraft.