BY indefinitely postponing his trip to Asia, President Bush has upset Japan's hopes to use his visit to smooth over critical issues between the two nations.Most critical to Japanese officials was a plan to have Mr. Bush and the new prime minister, Kiichi Miyazawa, sign a "Tokyo Declaration" outlining the future of bilateral cooperation. The proposed charter was seen as one way to fend off any revival of American resentment against Japan during the 50th anniversary of the Dec. 7 attack on Pearl Harbor. After receiving a telegram yesterday from Bush informing him of his decision, Mr. Miyazawa appeared crestfallen, especially since he had taken office only the day before and was counting on the president's visit for a foreign policy success. As a veteran statesman and a fluent English speaker, Miyazawa had been chosen as the new prime minister last month, in large measure for his diplomatic skills in dealing with the United States at a crucial time. He said yesterday that he regretted Bush's decision but understood the president's reasons. "There is no denying that [the postponement of Bush's visit] dampened the initial enthusiasm of the newly established Miyazawa administration, as it viewed the visit as a fine opportunity to establish a Japan-US global partnership with the post-cold- war New World Order in mind," said Japan's largest newspaper, Yomiuri. Early signs that the president was worried about Democratic charges that he traveled abroad too much came last week when US officials asked to shorten Bush's stay in Japan from nearly a week to just over two days, a move that concerned Japanese officials at the time. Bush had also planned to go to South Korea, Singapore, and Australia. BUSH, who would have been in Japan from Nov. 29 to Dec. 1, was long overdue for a visit in order to accommodate a Japanese sensitivity to diplomatic reciprocity. The previous prime minister, Toshiki Kaifu, made several trips to the US during the past two years without winning a return visit by Bush. A trip to the US by Miyazawa is being considered, according to the new foreign minister, Michio Watanabe, but only if Bush does not travel to Japan by early next year. The Bush visit was to have been used to address key trade issues just before the start of the US presidential campaign and at a time when Japan's share of the US trade deficit is rising. Topping the list of trade issues is whether Japan will follow a US request for it to open its rice market as a negotiating gesture for the Uruguay Round trade talks, which may reach a critical point in coming weeks. Miyazawa, speaking to reporters Tuesday, was more accommodating to settling the rice dispute than his predecessors. "We can't go on discussing this issue endlessly," he said. The Bush visit was to have come just before the resumption of US-Japanese talks in the so called Structural Impediments Initiative, in which Japan has promised various steps to change and open its economy. One US demand in the talks was for Japan's Federal Trade Commission to toughen its antitrust actions. On Tuesday, the FTC indicted eight Japanese chemical manufacturers for collusive price setting. The move was widely seen as designed to set the stage for a Bush visit.