SEOUL -- World leaders united in expressing alarm Tuesday at North Korea's decision to quit the UN nuclear watchdog agency, but there were signs of disagreement about the next move in the crisis. President Bill Clinton voiced deep concern, President Boris Yeltsin called the move "very serious" and Japanese Prime Minister Tsutomu Hata said the situation was grave. The Stalinist North, believed by the United States and its allies to be building nuclear weapons in defiance of the safeguards pact it signed, announced Monday it was pulling out of the International Atomic Energy Agency. The agency last Friday suspended technical aid to the North after it refused access to IAEA inspectors seeking evidence of a secret nuclear bomb. The North called the agency move a prelude to UN sanctions, adding: "We strongly reaffirm our position that UN 'sanctions' will be regarded immediately as a declaration of war." Pyongyang said it would no longer permit IAEA staff into the country but gave no indication whether it would tell two inspectors still there to leave. The North did not announce withdrawal from the Nuclear Nonproliferation Treaty, as it threatened to do since March of last year. The IAEA said this meant it was legally bound to accept inspections of its nuclear plants. In Washington the State Department said any removal of IAEA cameras or inspectors to monitor spent fuel removed from the North's Yongbyon nuclear reactor "would be a new and very dangerous development." The U.S. Ambassador to the United Nations Madeleine Albright said Monday the first draft of a sanctions resolution might be distributed with 24 hours. Clinton expressed deep concern in a call to Japanese Prime Minister Tsutomu Hata about Pyongyang's latest move, Japanese officials said. Hata, whose country has been threatened by Pyongyang with "deserving punishment" if it supports sanctions, described the situation as grave but added: "The United Nations must respond in one way or another." Clinton also called Yeltsin, and a White House spokesman said they "agreed on a general approach to sanctions." Yeltsin said he linked sanctions with a call for an international conference about security of the Korean Peninsula. This met with the cold shoulder from Clinton, Itar-Tass reported."We are pleased at Russia's participation in solving the North Korean nuclear problem, but we think the conference idea should not become an impediment to action by the UN Security Council," the Russian state news agency quoted Clinton as saying. Itar-Tass said Japan shared Clinton's views. China, North Korea's last major ally and biggest trading partner, has power to veto a Security Council sanctions resolution or abstain but ignore any embargo. It repeatedly called sanctions counterproductive and urged negotiations. There was no official word from Beijing on the North's latest move. But Vice Foreign Minister Tang Jiaxuan was quoted as blaming the IAEA for the North's withdrawal. "The IAEA sanctions caused this result, China abstained from voting" on those sanctions "and calls for a peaceful solution through dialogue," visiting Japanese politician Taku Yamasaki quoted Tang as telling him. "China is continuing consular efforts, we are doing this in a more positive way, but the North Korean attitude is very firm," Tang was quoted as adding. "I think our efforts will not be decisive."We are at a critical moment. The international community should promote a peaceful solution, mainly through dialogue between North Korea and the United States."In Seoul, a senior aide to South Korean President Kim Young-sam said "the North Korean announcement appeared to be aimed at intimidating the world."He and a Foreign Ministry spokesman said the South, would not be intimidated. "North Korea will have to recognize that countermeasures by the international community through a sanctions resolution in the UN Security Council will get firmer," spokesman Chang Ki-ho said. But in a sign that months of uncertainty are taking their toll, the Seoul stock market, closed down 2.11 percent. Foreign Minister Han Sung-joo said there were chances for the North to settle the issue through dialogue. "I want to emphasize that peaceful settlement is still our hope. We will continue to leave that possibility open."Former U.S. president, Jimmy Carter, headed for Pyongyang on Wednesday on a private peace mission, met Kim Tuesday to discuss the nuclear impasse. State radio said Kim emphasized the need for sanctions and asked Carter to tell the North Seoul was ready to provide aid in return for nuclear openness.