The Nuclear Non-Proliferation Treaty (NPT) was an agreement between countries that signed the treaty that there would be no more development or use of nuclear weapons. It also allowed for the surveillance of nuclear facilities by the IAEA also known as the International Atomic Energy Agency. This was signed by the United States, United Kingdom and Soviet Union and fifty-nine others on July 1, 1968. Other nations later signed onto this treaty. The only states that have chosen not to sign are Cuba, Israel, India, and Pakistan.