BEIJING, Sept. 26 (Xinhua) -- China urges Japan to act on its commitment to fully understand and respect the fact that "Taiwan is an inalienable part of the territory of the People's Republic of China," and urges it to cease official interactions with Taiwan under any pretext, Chinese foreign ministry spokesperson Guo Jiakun said at a regular press briefing on Friday.

Guo's remarks came after Taro Aso, former Japanese Prime Minister and supreme adviser of Japan's Liberal Democratic Party, said that "Taiwan is a country that shares fundamental values with Japan" in a meeting with the president of the so-called Legislative Yuan of the Taiwan region on Sept. 25.

"This is not the first time that certain Japanese politician has made provocations on the Taiwan question. This behavior constitutes a serious violation of the one-China principle and the guiding principles of the four political documents between China and Japan, and is a gross interference in China's internal affairs," Guo said. China deplores and is strongly opposed to these actions, and has made representations to Japan through diplomatic channels, he said.

Guo said that there is only one China in the world and that Taiwan is an inalienable part of China's territory, which is the real status quo across the Taiwan Strait.

The Cairo Declaration and the Potsdam Proclamation explicitly state that all of the territories Japan had stolen from the Chinese people, including Taiwan and the Penghu Islands, shall be restored to China -- and that was an important component of the post-war international order, Guo said.

"Taiwan is a province of China and has never been a country, and the Taiwan question bears on China's core interests, the political foundations of China-Japan ties, and the basic trust between the two countries," he said.

This year marks the 80th anniversary of victory in the Chinese People's War of Resistance Against Japanese Aggression, and also the 80th anniversary of the restoration of Taiwan. "Japan bears historical responsibilities to the Chinese people on the Taiwan question, and should act all the more prudently," Guo added.

China urges Japan to abide by the principles and spirit of the four political documents between the two countries, and to handle Taiwan-related issues properly, he noted.

"Japan must not make any provocation or dangerous move on the Taiwan question, and should not underestimate the firm resolve, will and ability of the Chinese people to defend their national sovereignty and territorial integrity," Guo said.  ■