A working-level delegation from the International Atomic Energy Agency (IAEA) arrived here Tuesday to discuss the shutdown of the Democratic People's Republic of Korea (DPRK)'s nuclear facilities at Yongbyon.

It is the UN watchdog's first visit to the Democratic People's Republic of Korea (DPRK) since late 2002, which came after U.S. nuclear envoy Christopher Hill paid a productive visit to the country last Friday.

Olli Heinonen, head of the delegation and IAEA deputy director general, told Xinhua at the airport that he was optimistic about the talks with his DPRK counterpart.

"We are going to negotiate arrangement for ratification of shutting down and sealing Yongbyon facilities with the DPRK during the three-day visit," he said.

Heinonen, who was greeted by Son Mon-san, head of the international department of DPRK's Atomic Energy General Bureau (AEGB), also added that they would make the plan of visiting the nuclear facilities at Yongbyon during their three-day visit.

Pyongyang invited an IAEA working-level delegation on June 16 to discuss shutting down the Yongbyon reactor, as required under an accord reached in China on Feb. 13.

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

Under the February agreement, the DPRK pledged to shut down the Yongbyon reactor within 60 days in exchange of 50,000 tons of heavy fuel oil or equivalent aid.

Hill said last Saturday the DPRK may shut down the Yongbyon nuclear facilities "within probably three weeks."

The IAEA visit came after the DPRK announced on Monday that the frozen fund dispute with the United States has been resolved. Pyongyang has insisted that its 25 million U.S. dollars frozen at the Banco Delta Asia in Macao be returned before the Yongbyon nuclear reactor is shut down and new negotiations are started.