NEW YORK (AP) — A former U.S. solder nicknamed Rambo has pleaded not guilty to charges that he agreed to help supposed Colombian drug traffickers kill a federal agent and an informant for $800,000.

Joseph Hunter entered the plea Saturday during a brief appearance at a federal courthouse in New York City. His lawyer declined to comment.

U.S. Attorney Preet Bharara says Hunter became a contract killer after he left the Army in 2004 and arranged several killings outside the United States.

Authorities say Hunter was a trained sniper who joined two other former soldiers from the U.S. and Germany in a plot to assassinate a Drug Enforcement Administration agent.

But the supposed Colombian drug traffickers were actually working for the DEA.

Hunter was extradited from Thailand on Friday.