Opium production has soared to "frightening record levels" in Afghanistan, which now has more land producing drugs than Columbia, Bolivia and Peru combined, the UN said on Monday.
The area of Afghan land where opium poppies are grown rose by 17 percent to 193,000 hectares in 2007 from 165,000 last year and this year's harvest was 8,200 tonnes, up from 6,100 tonnes in 2006, according to the latest report from the United Nations Office on Drugs and Crime (UNODC).
Afghanistan produced 93 percent of the world's opium in 2007, up from 92 percent last year, the annual UNODC report added.
"No other country has produced narcotics on such a deadly scale since China in the 19th century," a UNODC statement said.
Most Afghan opium is processed to make heroin and smuggled out of the country to Europe and the Middle East where it fuels addiction and crime.
Opium production in Afghanistan is concentrated in the south of the country where the Taliban insurgency is most virulent.
"Some 80 percent of opium poppies were grown in a handful of provinces along the border with Pakistan, where instability is greatest," the UNODC said.
The southern province of Helmand, where mostly British troops are engaged in almost clashes with Taliban rebels, produced more than half of Afghanistan's opium crop.
There is a direct link between the degree of insecurity and the level of drug production, the UNODC said, and tackling the Taliban insurgency is key to stemming opium cultivation.
"Where anti-government forces reign, poppies flourish," said UNODC Executive Director Antonio Maria Costa.
By contrast, in the more peaceful north of Afghanistan, there has been some progress. Out of 34 Afghan provinces, the number of those declared opium-free more than doubled to 13 in 2007 from six last year, mostly in the north and centre of the country.
Opium production has risen in Afghanistan every year in Afghanistan since U.S.-led forces toppled the Taliban from power in late 2001 and comes despite hundreds of millions of dollars of international aid spent trying to eliminate the problem.
The United States has budgeted $449 million to tackle opium production in Afghanistan in this year alone.
The UNODC said poverty and lack of alternative crops was not a factor influencing farmers' decision to plant poppies as the main growing regions in the south of the country had some of the richest and most fertile land in the whole of Afghanistan.
Taliban leader Mullah Mohammad Omar drastically reduced opium production in Afghanistan during his last year in power, issuing a religious edict banning the crop and threatening harsh punishments in areas the movement held under its strict control.
Now, the report said, the Taliban had reversed its policy.