The Bush administration underscored its continued support for Afghan President Hamid Karzai on Thursday despite fresh allegations from a former U.S. anti-drug official that Karzai is playing both sides of the effort to combat a raging drug business.

Thomas Schweich, who until June was one of the State Department's senior counter-narcotics officials, accused Karzai of protecting drug lords for political reasons. Schweich wrote in an article to be published Sunday in The New York Times magazine that "narco-corruption went to the top of the Afghan government."

Schweich said the Taliban-led insurgency fighting Karzai's government profits from drugs, but Karzai is reluctant to move against big drug lords in his political power base in the country's south, where most opium and heroin is produced.

"Karzai was playing us like a fiddle," Schweich wrote. The article appeared on the Times' Web site late Wednesday.

"The U.S. would spend billions of dollars on infrastructure development; the U.S. and its allies would fight the Taliban; Karzai's friends could get richer off the drug trade," he wrote.

State Department spokesman Gonzalo Gallegos did not directly address Schweich's allegations but defended U.S. policy and backing for Karzai.

"We know and understand that there is a corruption issue in Afghanistan but we're working with the sovereign government," Gallegos said Thursday. "President Karzai has shown us through word and deed that he is working with us to help improve the plight of that country."

Corruption is a deeply rooted problem and addressing it, along with the country's massive development need, will not be quick, Gallegos said. "This is a long-term commitment in terms of time and this is a large commitment in terms of dollars."

Afghan officials were not immediately available to respond to Schweich's allegations.

Drug production has skyrocketed since the U.S.-led invasion that ousted the Taliban regime. In 2007, Afghanistan produced 93 percent of the world's supply of opium, the raw material of heroin.

Karzai has repeatedly promised his U.S. backers that he is committed to rooting out endemic corruption and fighting the drug trade.

"Karzai had Taliban enemies who profited from drugs but he had even more supporters who did," wrote Schweich, who used to serve as coordinator for counter-narcotics and justice reform for Afghanistan. He was based in Washington.

Presidential elections in Afghanistan come next year, and Karzai has indicated he'll seek re-election.

Schweich accused the Pentagon and some U.S. generals of obstructing attempts to get military forces to assist and protect opium crop eradication drives.

NATO and U.S. military commanders have been reluctant to get involved in the drug fight, arguing that destroying farmers' crops would alienate tribesmen and increase support for the Taliban.

In 2003, about 198,000 acres of land was used to cultivate poppy. By 2007, it rose to 476,900 acres.

Opium production topped 9,000 tons, enough to make over 880 tons of heroin with a street value of $4 billion, according to the United Nations.

Figures for 2008 are not yet available.

The Ministry of Counter Narcotics says that 20 of Afghanistan's 34 provinces will be poppy-free this year — compared with 13 provinces in 2007. But in the south, cultivation remains rampant.