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 amid strained ties.
Relations between the world's second- and third-largest economies have been troubled for months because of a row over tiny 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.
It was not divulged what was said between Abe and Xi, but 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.
Chinese Foreign Ministry spokesman Qin Gang, speaking before the handshake, said his country's position on the islands is "clear-cut" and that they belong 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.