Doug Wankel, director of the U.S. counternarcotics task force in Afghanistan, says the country could be "taken down" by its drugs problem and evolve from its current narco-economy into a narco-state.
His comments come ahead of new UN opium crop data expected to show a massive increase in cultivation this year.
In other news, three people were wounded in eastern Afghanistan on September 2 when a car bomb exploded near a coalition convoy.
The wounded were a foreign soldier, an Afghan soldier, and an Afghan interpreter. The nationality of the coalition soldier was not released.
A spokesman for the U.S.-led coalition in Kabul could not confirm local police reports that the attack, in the Bati Kot district of Nangahar Province, had been carried out by a suicide bomber.
In another incident, NATO says one British soldier was killed and another seriously wounded in fighting in southern Afghanistan on September 1. The statement said militants attacked British soldiers in Helmand Province, where Britain has deployed nearly 4,000 troops as part of efforts to prevent the Taliban from reasserting its presence in Afghanistan.
In the southwestern province of Nimroz, four Afghan police officers and three suspected Taliban militants were killed on September 1 when militants ambushed a convoy. A district police chief was among those killed.
(compiled from agency reports)