Mullah Naim Barich, who operates as the "shadow governor" of the Taliban movement in Helmand province, was involved in the production and export of drugs such as opium from the province, the department said Thursday in a release.
Treasury officials also said Barich is involved in setting up the transportation of drugs and narcotics in Pakistan and Iran.
The Treasury Department action, taken under the Foreign Narcotics Kingpin Designation Act, prohibits U.S. interests from conducting financial or commercial transactions with Barich and freezes any assets he may have under U.S. jurisdiction.
"Today's action exposes the direct involvement of senior Taliban leadership in the production, manufacturing, and trafficking of narcotics in Afghanistan and underlines the Taliban's reliance on the drug trade to finance their acts of terror and violence," Undersecretary for Terrorism and Financial Intelligence David Cohen said. "Treasury will continue exposing links between the international narcotics trade and terrorist networks, in Afghanistan and wherever else they exist."