MOSCOW — The leaders of Russia and Japan have instructed their diplomats to intensify efforts to work out a peace treaty between the two nations.

Russia and Japan have yet to sign a formal peace treaty ending hostilities from World War II due to a dispute over four islands that were captured by Soviet forces at the end of the war. Nevertheless, they have pursued economic ties.

Russian President Vladimir Putin, who met Monday in Moscow with Japanese Prime Minister Shinzo Abe, said both countries told their foreign ministries to "intensify contacts for devising a mutually acceptable way of settling the problem."

"President Putin and I confirmed our understanding that it's an abnormal situation when 67 years have gone by after the end of the war between Japan and Russia and no peace agreement has been concluded," Abe said at a news conference following the talks.

There was no elaboration on possible compromise areas and Putin acknowledged that increased efforts "doesn't mean that everything will be resolved tomorrow."

In 2011, Russia vowed to deploy military hardware to the islands.

With rival China also pursuing closer energy cooperation with Russia, Japan has more incentive than ever to put its historical roadblocks with Russia aside.

Russian and Japanese companies signed an array of documents on the sidelines of the visit. Putin said the Russian natural gas monopoly Gazprom intends to participate in building an LNG terminal in Japan.

Russia's Far East is also keen to attract more Japanese investment in its energy sector and in the infrastructure construction it needs for closer trade ties with the rest of the Asia-Pacific region.

Since taking office in late December, Abe has sought to highlight Tokyo's interest in building closer ties with Southeast Asian nations to help drive economic growth and offset the fallout from tensions with Beijing over a territorial dispute in the East China Sea. He says "economic diplomacy" is a priority for reviving Japan's sluggish economy.

After Russia, Abe is due to visit Saudi Arabia, the United Arab Emirates and Turkey, where negotiations are underway for a major nuclear power technology deal, officials say.