An aide to Prime Minister Shinzo Abe on Tuesday sought U.S. support for Japan concluding a postwar peace treaty with Russia, saying closer Tokyo-Moscow ties will help counter a threat posed by China.

"Both Japan and Russia view China as a potential threat," said Katsuyuki Kawai, special adviser to Abe for foreign affairs.

"I would like the United States to understand the importance of concluding a Japan-Russia peace treaty as a means to jointly counter the threat from China."