In February, IAEA Director-General Mohamed ElBaradei visits Iran to talk with President Khatami and senior Iranian officials about the country's nuclear program. Iran confirms for the first time it is constructing two fuel enrichment plants at Natanz and a heavy water production plant at Arak.

North Korea declares its withdrawal from the NPT on January 10, stating then that its withdrawal "will come into force automatically and immediately" on the next day. The North Korean government claims that it had suspended its 1994 withdrawal from the treaty on the last day of the required three-month notice period and thus did not need to give further notice to other NPT parties and Security Council as required under Article X of the treaty.

Although no statement to this effect has been issued by the NPT state parties, the generally held view is that North Korea's withdrawal came into effect on April 10, 2003, when its three-month notice (which began on January 10, 2003) of withdrawal expired.

The IAEA Board of Governors adopts a third resolution (GOV/2003/3) on February 12, 2003, declaring that North Korea was "in further non-compliance with its obligations under its Safeguards Agreement pursuant to the NPT" and decided to report "to the United Nations General Assembly and the Security Council, North Korea's continued non-compliance and the Agency's inability to verify non-diversion of nuclear material that is subject to safeguards."

The IAEA and UNMOVIC withdraw from Iraq on March 18 when the U.S.- and U.K.-led coalition informs the inspectors that military action is imminent.

On March 20, the U.S.- and U.K.-led coalition begins military operations against Iraqi forces with the objective of disarming Iraq's WMD by force, toppling Saddam Hussein's ruling regime, and ensuring Iraq's inability to produce nuclear weapons.

Timor Leste accedes to the NPT on May 5.

The second session of the PrepCom for the 2005 NPT Review Conference is held in Geneva from April 28 to May 9.

On September 12, the IAEA Board adopts a resolution on nuclear safeguards in Iran setting a deadline (October 31, 2003) for Iran to provide information on its past and present nuclear activities.

On October 21, in agreement with the Foreign Ministers of France, Germany, and the United Kingdom, Iran declares that it would provide the IAEA with a full disclosure of all its past nuclear activities. Iran also agrees to conclude an Additional Protocol and suspend its uranium enrichment activities.

On November 7, the U.S. Congress authorizes the administration to conduct research leading to the development of new nuclear weapons, including the Robust Nuclear Earth Penetrator (RNEP) and low-yield nuclear weapons.

On November 26, the IAEA Board of Governors adopts a resolution on the implementation of nuclear safeguards in Iran, deploring Iran's past failures and breaches of its obligations to comply with the provisions of its Safeguards Agreement. The board, however, stopped short of declaring Iran in non-compliance with its treaty obligations.

On December 18, Iran signs the Additional Protocol to its Safeguards Agreement with the IAEA.

On December 19, Libya announces that it would halt its WMD programs and eliminate any stockpiles of weapons or materials under full verification by the international community.