islands, although Abe said: "The Japanese door to China is always open."
Russia has been strengthening political and energy ties with Beijing, and President Xi Jinping also attended the start of the Games in Sochi, but Moscow is also uneasy about China's rise and is keen to strengthen energy and trade ties in Asia.
Putin made an official visit to Japan in 2005, during his initial 2000-2008 presidency, and visited again as prime minister in 2009. Abe's visit in April was the first official visit to Moscow by a Japanese prime minister in a decade.
Abe and Putin have not let the islands dispute block progress in diplomacy, centring on natural gas and other natural resources.
By contrast, the leaders of Chinese and Korean leaders have rebuffed Abe's repeated calls to meet.
Some Russian oil flows are being redirected to Asia via the East Siberia-Pacific Ocean pipeline, and Russia plans to at least double oil and gas flows to Asia over the next 20 years as it turns away from export routes to Europe.
Japan sees this as an opportunity. It has been forced to import huge volumes of fossil fuel to replace its entire nuclear power industry, shut down after the 2011 earthquake and tsunami wrecked the Fukushima plant.
Japan now consumes a third of global liquefied natural gas shipments, a key reason for its record 18 months of trade deficits. Russian gas lies on Japan's doorstep and already makes up about a tenth of its LNG imports.