Status of CTBT Signatures and Ratification

Fact Sheet
Bureau of Arms Control, Verification, and Compliance

Key Point: As of July 31, 183 nations have signed the Comprehensive Nuclear Test-Ban Treaty (CTBT), and 159 have ratified it. Of the 44 Annex 2 States* whose ratification are specifically required by the CTBT for its entry into force, 41 have signed the Treaty and 36 have ratified it. There are eight Annex 2 States that have yet to ratify the Treaty - China, Egypt, Iran, Israel, and the United States of America, which have signed the Treaty, and North Korea, India, and Pakistan, which have not signed.

"Annex 2" States are the states that must ratify the Treaty and deposit their instruments of ratification with the Secretary-General of the United Nations for the Comprehensive Nuclear Test-Ban Treaty (CTBT) to enter into force. These 44 states are those that participated in the negotiation of the CTBT from 1994-1996 and that possessed nuclear power or research reactors at the time.

Progress Toward Ratification

President Obama announced his intention to pursue U.S. ratification of the CTBT in April 2009.