BEIJING, Nov. 1 (Xinhua) -- China expresses its firm opposition and has made serious demarches and protests to Japan over the Japanese leader's wrongful comment and action concerning Taiwan on the sidelines of APEC meetings, a foreign ministry spokesperson said on Saturday.

On both Oct. 31 and Nov. 1, Japanese Prime Minister Sanae Takaichi posted on social media photos and comments about her meeting and exchange with personnel of the authorities of China's Taiwan region during APEC Leaders' Week, referring to the person as "Senior Advisor to the Presidential Office of Taiwan."

In response to a relevant query, the spokesperson said that the Japanese leader deliberately met with the personnel of the authorities of China's Taiwan region during the APEC Leaders' Week and hyped it on social media, adding that those actions severely violated the one-China principle, the spirit of the four political documents between China and Japan, and basic norms of international relations, and sent a gravely wrong signal to the "Taiwan independence" forces.

"Those actions are egregious in nature and impact," said the spokesperson.

The spokesperson noted that the Taiwan question is China's internal affair and at the core of China's core interests. How it is handled bears on the political foundation of China-Japan relations and basic trust in Japan, and is a red line that must not be crossed.

This year marks the 80th anniversary of the victory of the Chinese People's War of Resistance against Japanese Aggression and the World Anti-Fascist War, and the 80th anniversary of Taiwan's restoration, the spokesperson said, pointing out that given its long history of colonial rule over Taiwan, Japan bears undeniable historical responsibilities on the Taiwan question and therefore should all the more act with extra prudence.

China strongly urges Japan to abide by the spirit of the four political documents between the two countries and honor the commitments Japan has made, reflect on and address its wrongdoings, take concrete measures to undo the negative impact, stop interfering in China's internal affairs, and act on its statement of building a constructive and stable China-Japan relationship fit for the new era, the spokesperson said.