ST PETERSBURG, Russia (Reuters) - Japanese Prime Minister Shinzo Abe and Chinese President Xi Jinping shook hands and exchanged words on Thursday on the sidelines of a G20 summit, the Japanese government 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.
"Even though it was a brief greeting, it means a lot. The Japanese and Chinese leaders directly exchanged words for the first time since taking office," Japanese Chief Cabinet Secretary Yoshihide Suga told reporters on Friday.
In the contact shortly before G20 leaders began their main session, Abe told Xi that the two countries should advance bilateral ties by upholding the spirit of mutually beneficial, strategic relationship, Suga said, without elaborating.
Xi told Abe that China-Japan relations were facing grave difficulties and 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, China's Foreign Ministry said.
Echoing Suga's upbeat view, China's official Xinhua news agency said in an English-language commentary that the exchange of words was a positive sign, but made it clear that it was Japan that needed to make a move to improve ties further.
"A polite encounter may be a good start, and it shows Beijing's willingness to bring its relations with Japan back on the right track, but whether that can happen still rests with Tokyo," the news agency said.
"It was Japan that triggered the 'grave difficulties' in bilateral relations, so it should be Japan that takes the initiative to break the stalemate."
The Japanese government bought three of the disputed islands from a private Japanese owner in September last year, prompting big protests and boycotts of Japanese goods in China.
Later in 2012, Abe returned to power for a rare second term, pledging to stand tough on the islands row.
Tension remains 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 it was "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.
At G20, Abe also exchanged greetings and stood chatting with South Korean President Park Geun-hye shortly before the leaders' dinner on Thursday, Japanese officials said.
Relations between Tokyo and Seoul have soured due to a separate territorial dispute and disagreement over their wartime past.
(Reporting by Tetsushi Kajimoto and Lidia Kelly; Additional reporting by Jonathan Standing and Ben Blanchard in BEIJING and Kiyoshi Takenaka In Tokyo; Editing by Stephen Coates and Robert Birsel)