In addition, the U.S. has also been involved in the development of the fungus Fusarium oxysporum to wipe out coca.[4][5] In 2000, the Congress of the United States approved use of Fusarium as a biological control agent to kill coca crops in Colombia (and another fungus to kill opium poppies in Afghanistan), but these plans were canceled by then-President Clinton, who was concerned that the unilateral use of a biological agent would be perceived by the rest of the world as biological warfare. The Andean nations have since banned its use throughout the region.