A top U.S. official says the importance of opium cultivation to Afghanistan's economy is declining.
Richard Boucher, the U.S. assistant secretary of state for south and central Asian affairs, says about one third of the Afghan economy was based on opium last year.
But he added that its production was diminishing due to the growth of the regular economy, including the cultivation of other crops.
He said more needed to be done to develop economic alternatives to opium production in Afghanistan. The country is the world's number one producer of opium, a key ingredient in heroin.
Boucher is attending an international conference in Berlin on the reconstruction of Afghanistan.
Last week, the Bush administration announced it would spend more than $10 billion in Afghanistan for security and reconstruction.
Some information for this report was provided by AP and Reuters.