The United States says efforts to help Colombia eradicate the coca crop are working, despite a 26 percent increase in coca cultivation areas from 2004 to 2005.

A new report by the U.S. Office of National Drug Control Policy says that although coca was discovered in new areas of Colombia during that time period, the government eradicated a record 170,000 hectares.

The U.S. report concludes coca plantings in Colombia have decreased in fumigated areas, and increased where no chemical spraying occurred. It says eradication efforts will focus on the new coca fields.

Money from drug trafficking has helped finance both the rightist paramilitary groups and Marxist guerrillas on opposing sides of Colombia's four-decade-long civil war.

Coca is the raw material used to make the illegal drug, cocaine. Colombia is the world's largest producer of cocaine.

The United States has provided Colombia with more than three billion dollars since 2000 to help it destroy coca crops, train and equip anti-drug units of its armed forces, and rebuild its judicial system.

Some information for this report was provided by AP.