The United States has decided to keep North Korea off its list of states that sponsor terrorism for the fourth year in a row.

The Country Reports on Terrorism 2011 issued by the State Department on Tuesday said that North Korea was excluded from the list, noting the North is "not known to have sponsored any terrorist acts" since the bombing of a Korean Air flight in 1987.

The State Department said North Korea was redesignated as a country that is "not fully co-operating" in the war on terrorism in line with the U.S. Arms Export Control Act.

The former administration of President George W. Bush took Pyongyang off the list of state sponsors of terrorism in return for its progress declaring the extent of its nuclear activities in October 2008.