Underground tests in the United States continued until 1992 ( its last nuclear test ) , the Soviet Union until 1990 , the United Kingdom until 1991 , and both China and France until 1996 . In signing the Comprehensive Nuclear-Test-Ban Treaty in 1996 , these states have pledged to discontinue all nuclear testing ; the treaty has not yet entered into force because of failure to be ratified by eight countries . Non-signatories India and Pakistan last tested nuclear weapons in 1998 . North Korea conducted nuclear tests in 2006 , 2009 , 2013 , 2016 , and 2017 . The most recent confirmed nuclear test in September 2017 in North Korea
most recent confirmed nuclear test
2017 North Korean nuclear test
Nuclear weapons testing