Three Chinese government ships were sailing in waters around islands disputed with Japan on Wednesday, a day after the Japanese premier suggested a summit could help mend frayed ties.
Japan's coastguard said the maritime surveillance boats were sailing in waters around a chain of Tokyo-controlled islands known as the Senkakus in Japan for about an hour and a half.
They all left the waters by 1:32 pm (0432 GMT), coastguard officials said.
China, which calls the islands the Diaoyus, has repeatedly sent ships to the area since Japan nationalised some of the chain in September. The move triggered a diplomatic dispute and huge anti-Japan demonstrations across China.
Beijing has also sent air patrols to the archipelago in the East China Sea and recently both Beijing and Tokyo have scrambled fighter jets, though there have been no clashes.
On Tuesday Prime Minister Shinzo Abe suggested a summit with China would improve a relationship that has been badly troubled for months.
"A high-level meeting should be held because there is a problem. If necessary, there might be a need to build the... relationship again, starting with a summit meeting," he told a television show.