Japanese Prime Minister Shinzo Abe said a summit with Russian President Vladimir Putin was needed to resolve the territorial issues over islands north of Hokkaido, which Japan calls its “Northern Territories,” the Associated Press (AP) reported. Japan and Russia did not sign a peace treaty after World War II and the territorial dispute is over four islands that Russia seized in 1945.

“We both recognize that 70 years after the war's end, to not have concluded a peace treaty is abnormal,” Abe said in a New Year address Monday in Tokyo. "But without a summit meeting this Northern Territories problem cannot be resolved," he added, according to AP. Giving examples of “normalizing” relations with China and South Korea, Abe reportedly said he hopes for further improvement.

Abe asked Russia to play a positive role in the Iran and Syria crises, and in fighting terrorism, reported the AP. The Japanese prime minister has been trying to improve relations between Tokyo and Moscow which have become complicated amid the latter's role in Ukraine, where Russia is accused of supporting pro-Russian rebels and annexing Crimea, among other issues. Several plans of Putin to visit Japan have been stalled due to concerns from Western powers over Moscow’s involvement in controversial crises, AP reported.

According to a report by Sputnik News, Putin was scheduled to visit Tokyo in fall 2014 but the trip got cancelled due to geopolitical tensions. Putin and Abe met in November on the sidelines of the G20 summit in Turkey but the former’s long-due visit to Japan in late 2015 has also been postponed indefinitely.

Russia reportedly wants to increase its investment in the far-east and Japan sees this as a good opportunity to discuss the territorial dispute with Moscow, according to the AP. While both the countries have tried to improve relations and to encourage the development of the disputed region, little progress has been made.