What is the Comprehensive Test Ban Treaty (CTBT)?
On September 10, 1996, the United Nations General Assembly voted 158-3 to approve a treaty prohibiting all nuclear tests. The Comprehensive Test Ban Treaty has been signed by 130 nations - including the United States. President Clinton signed the agreement on September 24, 1996.
A possible explosion of magnitude 5.3 occurred in North Korea on September 9, 2016 at 00:30:01 UTC (9:00 am local time).