Defense Secretary Donald H. Rumsfeld said Monday a flourishing drug trade in Afghanistan may be helping fuel a Taliban resurgence, potentially undermining the young Afghan democracy.

"I do worry that the funds that come from the sale of those products could conceivably end up adversely affecting the democratic process in the country," he told reporters accompanying him on an overnight flight from Washington.

"I also think anytime there is that much money floating around and you have people like the Taliban that it gives them an opportunity to fund their efforts in various ways," he added in the interview.

U.S. forces invaded Afghanistan in October 2001 to oust the radical Taliban regime, and although the country now has a democratically elected government the Taliban have made been making a comeback.

Rumsfeld said there is U.S. intelligence information indicating that the Taliban have taken a share of drug profits in exchange for providing protection. He did not offer specifics or elaborate.

The defense secretary also said the bulk of the demand for heroin and other drugs supplied by Afghanistan is largely in Europe and Russia, and he called on the Europeans to do more to help fight the problem.

"Western Europe ought to have an enormous interest in the success in Afghanistan, and it's going to take a lot more effort on their part for the Karzai government to be successful," he said, referring to President Hamid Karzai.

Tajikistan, which has supported U.S. anti-terror efforts including the war in neighboring Afghanistan, lies on a major route used by drug traffickers to smuggle narcotics to Russia an Eastern Europe. The United States has worked with the Tajik government to attempt to improve its border security.

Upon arrival in the Tajik capital, Rumsfeld was meeting with President Emomali Rakhmonov. Among the topics expected to come up is the Pentagon's interest in broadening its access to military bases in Tajikistan. Under an existing "gas-and-go" agreement, U.S. warplanes are permitted to stop in Tajikistan to be refueled but there is no arrangement for full-scale U.S. basing here.

In the in-flight interview — which came on Rumsfeld's 74th birthday — the defense secretary declined to discuss that subject in detail. But he indicated in general terms that the Pentagon is interested in finding more basing options to support war operations in Afghanistan.

"We obviously always need to be positioned so that we have more than one option," he said, referring to a basing arrangement in Kyrgyzstan — an arrangement now in doubt because of a dispute over U.S. payments and the Kyrgyz government's desire for more extensive political support from Washington.

"In any situation where you have only one way to do something you can become a captive," he added.

Rakhmonov, who has led the country since 1994, has jailed several former loyalists and opposition leaders and pushed through a referendum that would potentially allow him to stay in power until 2020 if re-elected. An election is scheduled for November.

Rumsfeld said this was his third visit to Tajikistan since the Sept. 11, 2001 terrorist attacks and the U.S.-led invasion of neighboring Afghanistan a month later. His most recent previous visit was in July 2005.

The U.S. military has no troops based in Tajikistan but the Tajik government has granted permission to overfly its territory on U.S. resupply missions into Afghanistan. Another neighboring state, Uzbekistan, kicked U.S. forces out in a dispute over the Uzbek government's handling of civil unrest in the eastern city of Andijan in May 2005. That diplomatic flap has added to the importance of Tajikistan as a strategic ally in the war on terrorism — in particular in prosecuting the war in Afghanistan.

In recent months Afghanistan has seen the bloodiest violence since U.S. troops invaded to oust the Taliban regime.

Some 10,000 U.S., Canadian, British and Afghan forces have deployed across southern Afghanistan as part of Operation Mountain Thrust in a bid to loosen the Taliban's grip on the region. At least 20 coalition troops have been killed in combat across Afghanistan since the offensive started in May, according to an Associated Press tally based on coalition figures. Most of the fatalities have been in the south.