Drug enforcement agencies asked Congress for an additional $780 million Wednesday to fight the rapidly expanding heroin (search) trade in Afghanistan.

The United Nations this week is expected to release new estimates for Afghan poppy (search) cultivation that show a marked increase over last year.

Poppies used to produce heroin are still only about 8 percent of the crops grown in Afghanistan, but there are a corrosive influence on the economy and the country's developing democracy, Assistant Secretary of State Robert B. Charles said.

The new money would go for a broad effort to eradicate poppies, help provide alternative crops or livelihoods for growers, find and prosecute traffickers and destroy production labs, Charles said.

The Drug Enforcement Administration (search) said the new effort expands its work with other countries in Europe and close to Afghanistan to choke the flow of drugs and chemicals used to manufacture them.

The agency said that about 895 pounds of heroin were seized in Afghanistan in 2002, before the interdiction effort began. During the first nine months of 2004, about 32,850 pounds were seized, the agency said.

The agencies want Congress to pay for the first year of the project with money previously planned for other international projects. Congress may hold hearings on the plan, which Charles compared to the U.S.-led "Plan Columbia" program to reduce cocaine production in that country.

The $780 million next year would be on top of several billions to be spent for aid to the new government of President Hamid Karzai (search) and to fund the lingering war in Afghanistan.

Congress recently approved $977 million in economic and military assistance for Afghanistan next year, making the country one of the largest recipients of foreign aid. The money includes $400 million to help train and equip the Afghan army, $350 million more than this year.

Separately, the Pentagon is spending an average of $769 million a month in Afghanistan.