WASHINGTON, March 1: The United States has begun an aggressive effort in Afghanistan to curb opium production, which has risen 20-fold over the past two years.

In a report submitted to the US Senate, Assistant Secretary Robert B. Charles, who heads the State Department's Bureau for International Narcotics and Law Enforcement Affairs, said the government intends to cut poppy cultivation, destroy drug labs, promote interdiction and seek the prosecution and conviction of drug traffickers.

Mr.Charles told the House Government Reform sub-committee on criminal justice, drug policy and human resources that Afghan President Hamid Karzai "means business - he is serious about tackling the heroin threat to his country.

"This is a leader who is dedicated to breaking the cycle of opium poppy cultivation and narcotics trafficking in his country before local trafficking rings become cartels and put down taproots, transforming Afghanistan into a narco-state," Mr. Charles said.