Russian Foreign Minister Sergei Lavrov said on Saturday, December 3 it would be difficult to close the gap in positions over a peace treaty with Japan, Reuters reports.

A territorial dispute between Tokyo and Moscow over a chain of western Pacific islands, seized by Soviet troops at the end of World War Two, has upset diplomatic relations ever since, precluding a formal peace treaty between the two countries.

Speaking at a joint briefing with Japan's Foreign Minister Fumio Kishida in Moscow, Lavrov also said a United States' anti-missile system in the Asia Pacific region presented a threat.