The Comprehensive Test Ban Treaty (CTBT) was opened for signature on September 24, 1996. President Clinton was the first to sign the Treaty. As of March 23, 1999, 152 nations have signed, including all five nuclear-weapon states, and 32, including France and the United Kingdom, have deposited their instruments of ratification.

The CTBT was negotiated over a period of two-and-a-half years in the Conference on Disarmament (CD) in Geneva. However, the CD was not able to reach a consensus decision to forward the text to the United Nations. On August 22, 1996, Australia requested the Secretary General of the United Nations to reconvene the 50th United Nations General Assembly (UNGA) for the purpose of receiving and acting on the Treaty. On September 10, 1996, the UNGA adopted the CTBT by a vote of 158 to 3, with 5 abstentions.

On November 19, 1996, the signatories adopted a resolution establishing the Preparatory Commission (Prepcom) for the CTBT Organization (CTBTO). The CTBTO Prepcom consists of all signatory states, and meets in Vienna. It has established two working groups, on verification and administration, and a Provisional Technical Secretariat (PTS). Under Prepcom direction the PTS is working to establish the verification regime required by the Treaty. This includes the International Monitoring System, with global monitoring capabilities in four technologies -- seismic, hydroacoustic, radionuclide, and infrasound; the International Data Center, for receiving and processing data from the monitoring stations; and capabilities for carrying out on-site inspections, once the Treaty enters into force.

The president transmitted the CTBT to the Senate in September 1997 for its advice and consent to ratification. In his January 19 State of the Union address, President Clinton called on the Senate to approve the Treaty this year, asking the Senate to "take this vital step, approve the Treaty now to make it harder for other nations to develop nuclear arms, and to make sure we can end nuclear testing forever."