The Status of the Comprehensive Test Ban Treaty: Signatories and Ratifiers

Last Reviewed
July 2024

Contact: Daryl Kimball, Executive Director, (202) 463-8270 x107

Despite nearly 20 years of global efforts to promote the entry into force of the Comprehensive Test Ban Treaty (CTBT), the treaty’s enactment appears a long way off.

President George H. W. Bush signed into law the unilateral declaration to forego full-scale nuclear weapons testing on October 2, 1992. The United States signed the CTBT on September 24, 1996, the day it opened for signature, but the Senate dealt a severe blow to the near-term prospects for U.S. participation when it refused to provide its advice and consent. On October 13, 1999. President Obama stated in February 2009 that he intended to pursue Senate advice and consent to ratification of the treaty "immediately and aggressively," but he ultimately did not do so. Although Russia ratified the CTBT in 2000, it withdrew its ratification of the CTBT in 2023 to "mirror" the posture of the United States; as a treaty signatory, Russia remains obligated not to take any action contrary to the object or purpose of the treaty.

The CTBT will formally enter into force after 44 designated “nuclear-capable states” (as listed in Annex 2 of the treaty) have deposited their instruments of ratification with the UN secretary-general. 

To date, 187 states have signed and 178 have ratified the treaty. Of the 44 specified countries, India, Pakistan, and North Korea still have not signed, and only 36 have ratified the treaty. For an up-to-date count of states-parties, please check the UNODA Treaties Database

For more information on the CTBT, see Comprehensive Test Ban Treaty at a Glance.