The United States keeps Cuba, Iran, Syria and Sudan on a list of state sponsors of terrorism.

The annual list is published in Reports on Terrorism.

Syria was included on the state sponsors of terrorism list on December 29, 1979.  Cuba was added to the list on March 1, 1982; and Iran was added on January 19, 1984.

Sudan was added to the list on August 12, 1993.  Unlike the other three designated sponsors of terrorism, the US State Department acknowledges that Sudan has fully cooperated with the United States to reduce the threat of terrorism.  However, citing concerns that the nation's security gaps have allowed terrorists to remain in the country, the US State Department decided to keep Sudan on the list.

"State Sponsors of Terrorism" is a designation applied by the United States Department of State to countries, which have “repeatedly provided support for acts of international terrorism.”

According to the U.S. Department of State's Office of the Coordinator for Counterterrorism, state sponsors of terrorism provide critical support to non-state terrorist groups.  “Without state sponsors, terrorist groups would have much more difficulty obtaining the funds, weapons, materials, and secure areas they require to plan and conduct operations.  Most worrisome is that some of these countries also have the capability to manufacture WMD and other destabilizing technologies that can get into the hands of terrorists.  The United States will continue to insist that these countries end the support they give to terrorist groups.”

Inclusion on the list imposes strict sanctions.  The sanctions which the US imposes on countries on the list are: a ban on arms-related exports and sales; controls over exports of dual-use items, requiring 30-day Congressional notification for goods or services that could significantly enhance the terrorist-list country's military capability or ability to support terrorism; prohibitions on economic assistance; and imposition of miscellaneous financial and other restrictions.

The list began on December 29, 1979, with Libya, Iraq, South Yemen, and Syria.

Iraq was and removed in 1982 to allow US companies to sell arms to it while it was fighting Iran in the Iran–Iraq War; it was put back on in 1990 following its invasion of Kuwait. The State Department's reason for including Iraq was that it provided bases to the Mujahedin-e-Khalq (MEK), the Kurdistan Workers Party (PKK), the Palestine Liberation Front (PLF), and the Abu Nidal Organization (ANO).  It was again removed following the 2003 invasion and the overthrow of the government of Saddam Hussein.  Following the invasion, US sanctions applicable to state sponsors of terrorism against Iraq were suspended on May 7, 2003 and President Bush announced the removal of Iraq from the list on September 25, 2004.

On May 15, 2006, the United States announced that Libya would be removed from the list after a 45-day wait period.

As far the North Korea is concerned, President George W. Bush announced on June 26, 2008, that he would remove North Korea from the list.  On October 11, the country was officially removed from the list for meeting all nuclear inspection requirements.

The North Korea was initially added to the list on January 20, 1988 because it reportedly sold weapons to terrorist groups and gave asylum to Japanese Communist League-Red Army Faction members. The country is also reportedly responsible for the Rangoon bombing and the bombing of Korean Air Flight 858.

South Yemen was dropped from the list in 1990 after it merged with the Yemen Arab Republic (North Yemen), to become Yemen.