United Nations nuclear watchdog inspectors confirmed Monday that North Korea shut down its main nuclear reactor, with agency chief Mohamed ElBaradei calling it "a very positive step." "The Yongbyon reactor has been shut down. We verified the shutdown of the reactor," Japan's Kyodo news agency quoted ElBaradei as saying in Bangkok, according to dpa. "We are going to verify the shutdown of the other facilities and by tomorrow (Tuesday) afternoon we will be able to report, hopefully, all of five facilities have been shut down," he said. North Korea had stated Sunday that the nuclear facilities at Yongbyon were shut down after receiving the first shipment of heavy oil from South Korea. The International Atomic Energy Agency (IAEA) inspectors later confirmed the shutdown the reactor, agency head ElBaradei said. Following six-nation talks, North Korea agreed in February to shut down the reactor in exchange for far-reaching economic and energy aid. On Friday a tanker containing 6,200 tons of heavy oil docked at a North Korea port and a second shipment of oil departed Monday. The second shipment of 7,500 tons will be followed by 43,800 tons expected to be sent to North Korea by August 1, said South Korea's Unification Minister Lee Jae Joung at a meeting with US envoy Christopher Hill. Hill, who arrived in Seoul on Sunday for a three-day visit, said the shutdown of the Yongbyon complex was a "good start," but that "we have really a lot of work to do now," after meeting with Lee, according to Yonhap news agency. We can talk about "next steps, not the last steps" when the six- way talks resume, Hill told Lee. In the coming weeks the IAEA team is to install cameras and other equipment to supervise the Yongbyon facility, 100 kilometres from the North Korean capital Pyongyang. Two inspectors are to remain on site. A new round of the talks involving the two Koreas, China, Japan, Russia and the United States are scheduled to resume in Beijing on Wednesday. Kyodo quoted ElBaradei as saying the six nations would next need to agree on how to disable North Korea's remaining nuclear facilities once Pyongyang provides an "inventory of all nuclear materials and facilities." Hill was to head to Beijing on Tuesday for a meeting with his North Korean counterpart Kim Kye Gwan. The shutdown comes after three months of delay caused by a US freeze on North Korean funds in a Macao bank. The transfer of the 25 million dollars to Pyongyang at the end of June left the way open for the implementation of the peace deal and the resumption of talks.