President Donald Trump announced on Tuesday that the U.S. will withdraw from the international nuclear accord with Iran , the landmark 2015 agreement curbing Irans nuclear development program in return for sanctions relief.

By ending Americas participation in the deal, Trump fulfills a major campaign promise. But the decision could set the stage for an international political crisis and uncertainty over the future of Irans nuclear program.

Heres what you need to know about the agreement:

The Deal

Also known as the Joint Comprehensive Plan of Action, the deal is the result of a decade of international negotiations to curb Tehrans nuclear ambitions.

Although Iran is banned from possessing nuclear weapons as a state party of the Nuclear Non-Proliferation Treaty, it failed to disclose the existence of its uranium-enrichment program for 18 years, causing alarm when its clandestine program was revealed in 2003.

Negotiators from Iran and six other world powers, including the United Nations Security Councils five permanent members and Germany, reached the historic agreement on July 14, 2015. It placed strict limits on Tehrans nuclear program that were set to last for more than a decade.

The United Nations Security Council endorsed the deal on July 20, 2015, officially agreeing to terminate U.N. sanctions on Iran.