The United States expressed concerns about peace and trade talks between Japan and Russia in recent months, pointing to western sanctions against Moscow which Tokyo has honored.
U.S. State Department spokesperson John Kirby said October 9 that "broadly speaking, it's not time for business as usual with Russia," as sporadic fighting continues between government forces and Russian-backed rebels in eastern Ukraine.
Kirby indicated that Japan's relations with Russia should proceed cautiously.
The deputy foreign ministers of Japan and Russia held seven hours of talks October 8, but they remained at odds over a long-running dispute over the Kuril Islands, which are claimed by both countries.
Japanese Minister Shinsuke Sugiyama afterwards described the negotiations as "tough" and said the territorial dispute remains a sticking point.
Russian diplomats called the dialog "constructive," however, and were optimistic about concluding an accord with Japan. The Kremlin has been arranging a visit to Japan by Russian President Vladimir Putin this year.
Putin met recently with Japanese Prime Minister Shinzo Abe on the sidelines of the United Nations General Assembly in an attempt to revive economic ties.