Although Japan joined with the Group of Seven industrialized nations in providing some technical and financial assistance to Russia, relations between Japan and Russia remained cold. In September 1992, Russian president Boris Yeltsin postponed a scheduled visit to Japan. The visit finally took place in October 1993. During the visit, although various substantive issues, including the Northern Territories and the signing of a peace treaty, were discussed, no significant improvement was seen in Japan-Russia relations. On July 30, 1998, the newly elected Japanese prime minister Keizō Obuchi had focused on major issues: signing a peace treaty with Russia, and reviving the Japanese economy from the 1997 Asian financial crisis. Unfortunately before his death, his policy with the Russian Federation has eluded implementation and the relations between the two nations remained without a state of peace. Economic relations Complicating economic relations between Japan and the Soviet Union were the Cold War realities and the above-mentioned territorial disputes. Imports from the Soviet Union declined during the first half of the 1980s, from nearly US$1.9 billion to less than US$1.5 billion, and then recovered to almost US$3.4 billion by 1990, representing modest growth for the entire period. Exports to the Soviet Union stagnated and then grew modestly, to over US$3.1 billion in 1988, before declining to US$2.6 billion in 1990. Commercial relations with the Soviet Union also paralleled strategic developments. Japan was very interested in Siberian raw materials in the early 1970s as prices were rising and détente persisted. The challenges to détente, especially the invasion of Afghanistan in 1979, and falling raw material prices put strong constraints on Japan's trade and investment relations with the Soviet Union. Only after Soviet policy began to change under Mikhail Gorbachev's leadership, beginning in 1985, did Japanese trade resume its growth. Japan's trade was also constrained by the Coordinating Committee for Multilateral Export Controls (CoCom), which controlled exports of strategic high technology. In 1987 the United States discovered that Toshiba Machine Tool had shipped machine tools on the restricted list to the Soviet Union, tools used to manufacture quieter submarine propellers. Although the Japanese government moved reluctantly to punish Toshiba (and the United States imposed sanctions on Toshiba exports to the United States in response), the outcome was stronger surveillance and punishment for CoCom violations in Japan. Ambassadors Soviet Union's ambassadors in Japan Vladimir Vinogradov – 1962–1966 Japan's ambassadors in the Soviet Union Mamoru Shigemitsu (1936–1938)