North Korea has moved disassembled parts of its main nuclear reactor back to the plutonium-producing facility in a step toward its restoration, South Korea's top diplomat said Thursday, according to AP. Foreign Minister Yu Myung-hwan expressed concern over the North's move and urged it to honor a disarmament pact. «It's not just words,» Yu told reporters. «They're putting words into action. I urge North Korea to stop any unilateral move and resume» disarmament. Yu said the North has placed «severed or removed equipment back to around the five-megawatt atomic reactor,» the country's sole operational reactor at the heart of its nuclear ambitions. Last week, Pyongyang had warned of such a move after halting work to disable the reactor and other facilities at Yongbyon, claiming Washington had failed to honor a pledge to remove it from a U.S. blacklist of states sponsoring terrorism under a deal reached last year. Washington has demanded that North Korea first agree to a plan to verify an accounting of its nuclear programs it submitted in June before being taken off the list. Yu said the North informed U.S. personnel stationed at its Yongbyon nuclear plant Tuesday that it planned to reassemble its atomic facilities and started moving disassembled equipment on Wednesday. The U.S. played down North Korea's latest actions. «Based on what we know from the reports on the ground, you don't have an effort to reconstruct, reintegrate this equipment back into the facility,» State Department spokesman Sean McCormack said. In Tokyo, Chief Cabinet Secretary Nobutaka Machimura said Japan was in close contact with the U.S. and South Korea on the development. «We are aware that (North Korea) is engaged in an activity to take some of the key equipment out of storage, and we are concerned about the situation,» he said. In Beijing, China, which for five years has sponsored international talks on the North's nuclear disarmament, called for all parties to continue working to move the disarmament process forward. «As to the current problems that have emerged, the relevant parties should enhance coordination and communication and exert flexibility and join hands to resolve the problems and press ahead with the six-party talks,» Chinese Foreign Ministry spokeswoman Jiang Yu told a news conference.