ST PETERSBURG, Russia Japanese Prime Minister Shinzo Abe and Chinese President Xi Jinping shook hands and exchanged words politely on Thursday on the sidelines of a G20 summit meeting, a Japanese official said, in an unexpected show of cordiality.
Relations between the world's second- and third-largest economies have been troubled for months because of a row over tiny uninhabited islands in the East China Sea known as the Senkaku in Japan and the Diaoyu in China.
There are also disputes over the countries' wartime past.
Abe is keen to improve ties and has called for dialogue with China, though he has rejected any conditions on talks. China has shown no inclination to respond to the overtures.
A Japanese government official said the contact took place shortly before G20 leaders began their main session and the two met for about four to five minutes and spoke through interpreters.
In a later report, China's official Xinhua news agency said that Xi told Abe that China-Japan relations were facing grave difficulties, a situation China is "unwilling to see."
Ties have been strained for months because of a row over a the islands as well as disputes over the countries' bitter wartime past.
Xi reiterated China's position that Japan should correctly deal with such sensitive issues by facing up to its history and seeking "a way to properly manage differences and address the problems", Xinhua reported.
It added that Abe said he had been looking forward to seeing Xi and was eager to improve Japan-China relations.
Tensions remain high surrounding the islands, with aircraft and ships from both countries playing cat-and-mouse games near them for months.
Chinese Foreign Ministry spokesman Qin Gang, speaking before the meeting between Xi and Abe, said Beijing had been "clear-cut" that the islands belonged to China.
"China-Japan relations are faced with serious difficulties now, but the responsibility rests not with China," Qin told reporters at a briefing.
"The different views between China and Japan of this issue should be effectively managed through consultations," he said of the islands.