The White House blasted Iran in its "National Strategy for Combating Terrorism" released on Tuesday for allegedly sponsoring terrorism.
"Iran remains the most active state sponsor of international terrorism," the 23-page report said.
"Through its Islamic Revolutionary Guard Corps and Ministry of Intelligence and Security, the regime in Teheran plans terrorist operations and supports groups such as Lebanese Hezbollah, Hamas, and Palestine Islamic Jihad (PIJ)," the report said.
"Iran also remains unwilling to account for and bring to justice senior Al-Qaida members it detained in 2003," it added.
Iran has been on the U.S. list of "state sponsors of terrorism" and the United States has been trying to impose sanctions on Iran for its defiance on its nuclear issue.