Japan recalled its ambassador to China for consultations on Sunday amid a simmering row between the Asian powers over disputed territory in the East China Sea, reports said.
Uichiro Niwa had returned to Tokyo for talks with Foreign Minister Koichiro Gemba on the latest developments in the dispute, they said.
"I will report and have consultations" with Gemba, Niwa told reporters as he arrived at the foreign ministry in Tokyo, according to Jiji Press.
Niwa said it had yet to be decided when he would return to Beijing. "But I think I will have to return after finishing the talks," he was quoted by Kyodo News as saying.
Gemba has denied the government was recalling Niwa in protest against China, insisting that his return home was for consultations, Japanese media reported.
Japan last week lodged two separate complaints with Beijing after Chinese vessels entered resource-rich waters claimed by both Tokyo and Beijing near a group of islands known as Senkaku in Japanese and Diaoyu in Chinese.
It also summoned the Chinese ambassador after the first incident.
China, meanwhile, expressed its strong opposition to a Japanese plan to buy the islands from the family that Tokyo recognises as the legitimate owner.
Despite the importance of the two nations' trading ties, relations between Japan and China are frequently tense, particularly over the territorial dispute and Japan's war-time aggression in Asia.
China has pressed its claim to waters far from its coast more energetically over the last few years as it has increased in both economic and military might.