Afghan opium cultivation and production dropped in 2008 for the first time in three years, partly because of drought, with almost all the illegal crop grown in unrest-hit areas, the UN said Tuesday.

The destitute country produces around 90 percent of the world''s opium, used to make heroin sold in Europe and Central Asia, with production reaching record levels last year and profits said to feed a Taliban-led insurgency.

Last year, the world was "hit by a heroin tsunami," Antonio Maria Costa, executive director of the United Nations Office on Drugs and Crime, said in a statement. "This year the opium flood waters have started to recede."

The UN agency, in a report on its annual poppy survey, said there was a 19 percent decrease in opium cultivation to 157,000 hectares (388,000 acres), down from a record harvest of 193,000 hectares in 2007. It marked the first drop in cultivation since 2005.

The drop was due to strong government leadership in certain areas that discouraged farmers from planting opium, the report said.

But government-led eradication of fields was not a factor. Last year the total area of poppy crops destroyed was much greater.

Drought also contributed to crop failure, particularly in the north and northwest, where most of the opium cultivation is rain-fed, the report said.