TOKYO,June 23 (Xinhua) -- Chief U.S. nuclear envoy Christopher Hill said here Saturday the Democratic People's Republic of Korea (DPRK) may shut down the Yongbyon nuclear facilities "within probably 3 weeks."

    Hill made the comments on arriving at the Haneda airport after a surprise visit to Pyongyang earlier this week, making efforts for the restart of the six-party talks over the denuclearization issue on the Korean Peninsula.

    The U.S. assistant secretary of state also said that he expected the next round of six-party talks to re-open earlier next month, which involve the DPRK, the United States, China, Japan, South Korea and Russia.

    Hill will hold talks with chief Japanese nuclear negotiator Kenichiro Sasae in the afternoon and briefed him on his visit to the DPRK.