TOKYO, Dec. 16 (Xinhua) -- Russian President Vladimir Putin said on Friday that the isles row between Russia and Japan can not be solved soon.

Putin, who is on a two-day visit to Japan, made the remarks at a joint press conference after his meeting with Japanese Prime Minister Shinzo Abe.

Abe, for his part, said the path towards resolving issues that have prevented Japan and Russia from signing a postwar peace treaty is difficult.

Over 70 years after the end of World War II, Russia and Japan have not yet signed a peace treaty, formalizing the end of the war, mainly due to a territory row over four small islands in the Pacific which are called the Northern Territories in Japan and the Southern Kurils in Russia.

Meanwhile, Japan and Russia agreed on Friday to start consultations on joint economic activities on the four Pacific islands, held by Russia but claimed by Japan.

The two sides agreed that joint activities would be conducted "under a special framework" and it would mark an important step towards reaching a postwar peace treaty between the two countries, according to a press statement here after the leaders' meeting.

The statement, however, did not touch upon any progress regarding the row over sovereignty of the four Pacific isles.

Russia suggested joint economic activities to Japan on the disputed islands in November, but there have been concerns in Japan that if Japan accepts the suggestion, it would mean a big step towards Moscow by recognizing Russian control of the islands.

The two sides signed here a total of 80 documents, including 68 private sector deals.

Putin, whose visit was initially eyed in 2014 but postponed due to deterioration of bilateral ties following the Ukraine crisis, is the first Russian president to travel to Japan for a bilateral meeting in 11 years.