Japan's relations with Taiwan are nongovernmental and practical and are based on Tokyo's recognition of the People's Republic of China as the sole legitimate government, a top Japanese official said on Friday, following Beijing's protest over a recent reference to the island as "a country".

Japanese Chief Cabinet Secretary Katsunobu Kato told a regular news conference on Friday that "Japan's position is to maintain working relations with Taiwan at the nongovernment level", in line with the 1972 Japan-China Communique.

"That's our basic policy and there is no change to that," he said.

Kato's remarks came a day after Japanese Prime Minister Yoshihide Suga made the reference to Taiwan during a parliamentary debate. Suga, while answering a question about pandemic, made a passing reference to Taiwan, New Zealand and Australia as "three countries".

China on Thursday expressed strong dissatisfaction with remarks by Suga and has lodged solemn representations with Japan, said Foreign Ministry spokesman Wang Wenbin.

Wang said the Japanese leader has openly referred to Taiwan as "a country", which seriously violated the principles of the four political documents including the China-Japan Joint Declaration, and breached the solemn promise of "not regarding Taiwan as a country" made by the Japanese side many times so far.

China wants Japan to immediately issue clarifications to eliminate the damage and to ensure that such a thing will not occur again, he said.

There is only one China in the world and Taiwan is an inseparable part of China's territory, said Wang, adding the Taiwan question concerns the political foundation of China-Japan ties, the basic credibility between the two countries, and the international rule of law and justice.

Xinhua and agencies contributed to this story.