China firmly opposes Japanese Prime Minister Sanae Takaichi's continuous undermining of the political foundation of China-Japan relations, which is based on the spirit of the four political documents between the two countries, a foreign ministry spokesperson said Thursday.

It was reported that Takaichi said on Wednesday at the debate with opposition party leaders that "having renounced all rights and claims under the Treaty of San Francisco, we are not in a position to recognize Taiwan's legal status."

In response, spokesperson Guo Jiakun told a regular news briefing that China's recovery of Taiwan is a victorious outcome of World War II and an integral part of the postwar international order. A series of instruments with legal effect under international law, including the Cairo Declaration, the Potsdam Proclamation, and the Japanese Instrument of Surrender, have all affirmed China's sovereignty over Taiwan.

The question regarding the status of Taiwan was already resolved once and for all when the Chinese people won the victory of the War of Resistance against Japanese Aggression in 1945. On Oct. 1, 1949, the Central People's Government of the People's Republic of China (PRC) was established and has since been the sole legal government representing the whole of China. This is a change of government in which China, as a subject under international law, did not change and China's sovereignty and inherent territorial boundaries stayed unchanged, Guo said, adding that thus, the government of the PRC naturally and fully enjoys and exercises China's sovereignty, including sovereignty over the Taiwan region.

He said the 1972 Sino-Japanese Joint Statement states that "The Government of Japan recognizes the Government of the People's Republic of China as the sole legal Government of China. The Government of the People's Republic of China reiterates that Taiwan is an inalienable part of the territory of the People's Republic of China. The Government of Japan fully understands and respects this stand of the Government of the People's Republic of China, and it firmly maintains its stand under Article 8 of the Potsdam Proclamation."

The so-called "Treaty of San Francisco" was issued with the exclusion of important parties to the WWII, such as the PRC and the Soviet Union, in order to seek a separate peace deal with Japan. The document goes against the provision that each government pledges not to make a separate armistice or peace with the enemies in the Declaration by United Nations signed by 26 countries in 1942, including China, the U.S., the UK and the Soviet Union, and violates the UN Charter and the basic principles of international law, he said.

"Anything set out in the treaty, including on the sovereignty over Taiwan or the handling of the territory and sovereign rights of China as a non-signatory, is thus entirely illegal and null and void," Guo said.

He said Prime Minister Takaichi deliberately chose not to mention the Cairo Declaration and the Potsdam Proclamation -- two international legal documents with full effect and underscored in the Sino-Japanese Joint Statement, the Treaty of Peace and Friendship Between China and Japan and other bilateral treaties, noting that she singularly brought up the illegal and invalid "Treaty of San Francisco."

That once again shows that the prime minister remains unwilling to own up to the wrongdoing and turn back from the erroneous course, continues to damage the political foundation of China-Japan relations established under the spirit of the four political documents between the two countries, shows no regard for the authority of the UN and openly challenges the postwar international order and basic norms in international law, and even seeks to play up the so-called notion that Taiwan's status is undetermined. That just compounds the wrongdoing, Guo said.

"China firmly rejects that and calls for utmost vigilance from the international community. We once again urge the Japanese side to reflect on and correct its wrongdoing, retract the erroneous remarks, and take practical steps to honor its commitments to China and do what is least expected of Japan as a UN member state," he said.