MOSCOW, November 19. /TASS/. Russian-Japanese cooperation in space research is underdeveloped because the two countries did not sign a peace treaty yet, director of Russian Academy of Sciences Institute of Space Research Lev Zeleny told reporters on Wednesday.

“Our cooperation with Japan is underdeveloped. We are working much to share the data with Japanese partners, but no peace treaty hampers us to have treaties on outer space exploration as those we have with Europe, the United States and other countries,” the scientist said.

The Soviet Union and Russia as its legal successor did not ink a peace deal after the end of the Second World War yet. The problem of the Kuril Islands remains main unsettled issue in bilateral ties.