Afghanistan is on its way to becoming a "narco-state" and U.S. and NATO-led forces in the country should get involved in fighting the drug trade as well as terrorists, according to a United Nations report released Thursday. "It would be an historical error to abandon Afghanistan to opium, right after we reclaimed it from the Taliban and al-Qaida," said Antonio Maria Costa, executive director of the U.N. Office on Drugs and Crime. The agency found that this year's cultivation of opium _ the raw material for heroin _ was up by nearly two-thirds. Bad weather and disease kept production from setting a new record, although it still accounted for 87 percent of world supply, up from 76 percent in 2003. The illegal trade is booming despite political progress in the country, including the first presidential election, and local drug control efforts directed by British military advisers. Opium is now the "main engine of economic growth and the strongest bond among previously quarrelsome peoples," according to the report. It valued the trade at US$2.8 billion (¤2.15 billion), or more than 60 percent of Afghanistan's 2003 gross domestic product. Calling the problem too big for the weak Afghan government to tackle alone, Costa said U.S.- and NATO-led forces should participate in military operations against drug labs and convoys of traffickers. --more 1322 Local Time 1022 GMT