China is gravely concerned about the potential expansion of the Australia-United Kingdom-United States trilateral security alliance, saying that it would severely undermine peace and stability in the Asia-Pacific region, the Ministry of National Defense said on Thursday.

Wu Qian, the ministry's spokesman, made the remarks at a news conference in Beijing in response to reports that Japan has expressed its intention to join AUKUS and that Canada is considering starting negotiations on joining the security alliance.

"We are open to normal military cooperation between any countries, but we firmly oppose relevant countries forming exclusive groupings, building bilateral or multilateral military alliances targeting China, creating division and stoking bloc confrontation," he said.

The Asia-Pacific region is a big stage for peace and development, not an arena for geopolitical competition, said Wu, emphasizing that "China is a cooperation partner for all countries, not a challenge to anyone".

Disregarding the concerns of regional countries and the international community, the US, the UK and Australia have kept sending signals about the expansion of AUKUS, which has severely undermined peace and stability in the Asia-Pacific region, he said, adding that many regional countries are deeply concerned about this.

Wu noted that, for historical and practical reasons, Japan's military and security moves are closely watched by its Asian neighbors and the international community.

"Japan needs to draw lessons from history and speak and act prudently on military and security issues," he said.

"Other countries should also earnestly fulfill their international obligations and avoid doing things that may undermine regional and world peace and stability," Wu added.

He also rebutted recent comments by some US senior officials regarding the Taiwan question, saying that all destabilizing activities in the Taiwan Strait come from interference and trouble-making by the US.

He underscored that if the US truly hopes to maintain peace and stability in the Taiwan Strait, it should immediately cease interfering in China's internal affairs, halt all arms sales to Taiwan, and put an end to all "official exchanges" and "military contacts" with Taiwan.

Earlier this month in an interview with Japanese public broadcaster NHK, US National Security Advisor Jake Sullivan claimed that the US would take every step it can to maintain peace and stability across the Taiwan Strait, adding that every party involved should take steps to avoid "destabilizing activities".

In addition, US Deputy Secretary of State Kurt Campbell suggested that Australian nuclear-powered submarines acquired under the AUKUS alliance could eventually be deployed against China in any military conflict over the Taiwan island, according to Australia-based ABC News.

Wu said that the AUKUS alliance is a product of the Cold War mentality upheld by the US, the UK, and Australia. "It will only exacerbate tensions, provoke confrontation, and disrupt peace. Regional countries, including China, express serious concerns and resolute opposition to such actions."

Any attempt to interfere in the Taiwan question through military cooperation constitutes meddling in China's internal affairs, violates the one-China principle, and undermines the basic norms of international relations, posing a threat to peace and stability in the Taiwan Strait, said the spokesman.

"The People's Liberation Army shoulders the sacred duty of safeguarding national sovereignty and territorial integrity, and will never stand idly by or show any mercy to 'Taiwan independence' separatist activities and external connivance and support," he said.