Aug. 9 (Bloomberg) -- Afghanistan's religious leaders decreed poppy cultivation, which makes the country the world's biggest opium producer, illegal, a move that will aid efforts to end the $2.3 billion drugs trade, the United Nations said.

Afghanistan's Council of Ulemas earlier this month issued a fatwa, or religious decree, saying the cultivation, processing trafficking and consumption of drugs must be prevented, said Mohammad Reza Amirkhizi, the representative in the country of the UN Office on Drugs and Crime, according to a UN statement.

The order ``sends a clear message that opium poppy cultivation, even if it is not consumed by Muslims or if it is done out of poverty, is illegal,'' Amirkhizi said.

The UN estimates 1.7 million Afghans, out of a population of 28 million, are directly involved in poppy cultivation. Afghanistan last year produced three-quarters of the world's opium, the U.S. State Department said earlier this year. The UN is organizing a $25 million five-year project aimed at ending the dependence of Afghan farmers on cultivating the opium poppy, the raw ingredient in heroin.

The order issued by the religious leaders clarifies that cultivation of the opium poppy is forbidden, Amirkhizi said. While Afghans have long understood that Islam prohibits the consumption of narcotics, there was confusion whether poppy cultivation was illegal, he said.

Afghanistan's 2003 opium production reached 3,600 metric tons, a 6 percent increase over the previous year, according to a UN report. The trade generates $1 billion in income for farmers and $1.3 billion for traffickers, it said. Afghanistan's gross domestic product was estimated at $700 for each citizen in 2002, according to U.S. government data.

Taliban Ban

Afghanistan's Taliban enforced a ban on cultivating the opium poppy from July 2000 until the regime was overthrown in December 2001 in the U.S.-led war against terrorism. The country's opium production fell to 185 tons in 2001 from a peak of 4,565 tons in 1999, a UN report said at the time.

Regions growing the opium poppy expanded from 28 to 32 last year, Robert Charles, the U.S. assistant secretary of state for international narcotics and law enforcement, said in March. The crop size last year was an estimated 61,000 hectares (150,600 acres), almost double the area in 2002, he said.

To contact the reporter on this story: Paul Tighe in Sydney at ptighe@bloomberg.net

Last Updated: August 8, 2004 19:28 EDT