BEIJING, July 15 (Xinhua) -- The nuclear issue on the korean Peninsula recorded a further progress Saturday as the DPRK announced the shutdown of its Yongbyon nuclear facilities after the arrival of a group of U.N. inspectors.

    The shutdown, which was widely regarded as a substantial step, was announced by the United States.

    "The U.S. has been informed Saturday that the Democratic People's Republic of Korea (DPRK) shut down its nuclear facilities at Yongbyon," U.S. State Department spokesman Sean McCormack said in a statement.

    "We welcome this development and look forward to the verification and monitoring of this shutdown by the International Atomic Energy Agency (IAEA) team that has arrived in the DPRK," he said.

    The Yongbyon reactor, located some 90 km north of Pyongyang, is regarded as the DPRK's leading nuclear research center.

    The announcement came only hours after a 10-member team of U.N. inspectors arrived here to verify and monitor the sealing of the nuclear facilities.

    Upon his arrival in Pyongyang, Adel Tolba, head of the IAEA inspection team, refused to answer any questions from awaiting reporters.

    "I have no comment, we have just come here to do our work, then make a report to Vienna headquarters," said Tolba.

    An official from the DPRK's general atomic energy administration told Xinhua at the airport that the inspection team would go straight to Yongbyon as soon as they picked up their luggage.

    The inspection team will monitor and verify the shutdown of the Yongbyon nuclear facilities as agreed upon between the IAEA and the DPRK and approved by the UN nuclear watchdog's board of governors.

    At a special session on Monday, the IAEA's 35-nation board of governors approved a report submitted by IAEA chief Mohamed ElBaradei on the mission to Yongbyon. The ratification of the report provided legal basis for the IAEA's new mission.

    On Saturday morning, a South Korean ship carrying 6,200 tons of heavy fuel oil arrived at the northeastern port of Songbong in the DPRK.

    The DPRK Foreign Ministry said last Friday that it will start suspending the operation of its nuclear facilities from the moment the first shipment of heavy oil arrives.

    The DPRK expelled IAEA nuclear inspectors in December 2002, and in January 2003, it publicly withdrew from the nuclear Non-Proliferation Treaty.

    Under the February agreement reached during the six-party talks,the DPRK pledged to shut down the Yongbyon reactor within 60 daysin exchange for 50,000 tons of heavy fuel oil or equivalent aid.