BEIJING, July 14 (Xinhua) -- In the late 1950s, the United States secretly transported tactic nuclear weapons to South Korea and deployed them in that country. The Democratic People's Republic of Korea (DPRK) then joined the nuclear Non-Proliferation Treaty (NPT) in December 1985, so as to force the United States to remove the weapons. However, the DPRK had never joined the Convention on Nuclear Safety with the International Atomic Energy Agency (IAEA) as the treaty required, due to the nuclear threat in the peninsula.

    The United States revealed in 1991 that the DPRK was developing nuclear weapons in its nuclear facilities in Yongbyon, and further demanded an investigation into the country's nuclear activities. The DPRK, nonetheless, claimed that the investigation should be conducted in U.S. military bases in South Korea as well. South Korea hosted the fifth premiers' summit with the DPRK in December 1991, during which South Korea agreed for the first time to undertake the international nuclear investigation. Thus, the two sides reached the Han Peninsula Non-Nuclear Common Manifesto on December 31, 1991.

    Later in January 1992, the DPRK signed the Convention on Nuclear Safety with the IAEA. Then IAEA Chief Hans Blix paid a visit to the DPRK in May, and an IAEA investigation team was subsequently sent to the DPRK.

    The DPRK announced on March 12, 1993 that the country would withdraw from the Treaty within three months, since the IAEA wanted to inspect its military facilities. However, the country retracted the announcement in June.

    In October 1994, the United States and the DPRK signed a framework agreement on the DPRK's nuclear issue. In accordance with the agreement, the IAEA would send long-term staff to the country to take charge of the inspection of nuclear facilities.

    The DPRK nuclear issue escalated in October 2002. The IAEA passed a resolution on November 29, demanding the DPRK abandon itsnuclear ambitions and open "all the related facilities" to the agency's inspectors. The DPRK asked the U.N. nuclear watchdog to stop all inspection activities on its territory on December 31 and publicly withdrew from the Nuclear Non-Proliferation Treaty in January 2003. The agency later passed several resolutions in a bid to call for the DPRK's cooperation and persuade it to accept comprehensive IAEA safeguards.

    The Chinese government has made positive efforts for a peacefulsolution for the DPRK's nuclear issue and finally brokered the six-party talks involving China, the DPRK, the United States, the Republic of Korea (ROK), Russia and Japan. After the third sessionof the fifth round of the six-party talks concluded, an agreement was reached on February 13, 2007, under which the DPRK agreed to shut down and seal off its Yongbyon nuclear facilities and invite IAEA officials to return to the DPRK for the necessary inspection and supervision.

    At the invitation of the DPRK, the IAEA chief Mohamed ElBaradeivisited the DPRK on March 13-14, 2007, the first visit by an IAEA chief since Hans Blix visited the DPRK in 1992.

    Pyongyang invited ElBaradei to discuss shutting down the Yongbyon reactor on June 16. An IAEA working-level delegation thenvisited the DPRK on June 26-30 to inspect the Yongbyon nuclear facilities and hold talks with the officials of the DPRK's Atomic Energy General Bureau.

    At a special session on July 9, the IAEA's board of governors agreed to send inspectors to verify and monitor the shutdown and sealing of the nuclear facilities in Yongbyon.

    On July 14, 2007, a 10-member team of IAEA inspectors arrived in Pyongyang to verify and monitor the shutdown and sealing of thenuclear facilities in Yongbyon.