In response to reports suggesting that Japan may soon join the Aukus security pact, China's foreign ministry expressed grave concerns on Monday. The move, if realized, would "disregard the risk of nuclear proliferation" and "intensify the arms race in the Indo-Pacific region," warned Mao Ning, the foreign ministry spokeswoman, during a daily press briefing.

The United States, Britain, and Australia are reportedly set to announce talks on expanding the Aukus alliance, with Washington pushing for Japan's inclusion as a deterrent against China. Financial Times reported that talks would take place on Monday to explore the possibility of bringing new members into the defense alliance.

Mao emphasized that China strongly opposes the formation of exclusive circles and bloc confrontations, urging Japan to exercise caution in its military security decisions. She also called on Japan to learn from historical lessons.

Formed in 2021, the Aukus security pact aims to counter China's growing influence in the Indo-Pacific region. China has previously voiced its concerns about the pact, warning that it could lead to a regional arms race.

According to the Financial Times, the three defense ministers of the Aukus alliance are set to announce talks related to Pillar II of the pact, which focuses on collaboration in military technologies such as quantum computing, artificial intelligence, hypersonic weapons, and undersea capabilities.

US President Joe Biden has actively sought to strengthen partnerships with allies in the Asia-Pacific region, including Japan and the Philippines, as China continues to engage in a rapid military build-up. Japan is seen as a natural candidate for joining the Aukus alliance, given its critical role as an ally in the region for each member country.

Further discussions regarding Japan's involvement in the Aukus pact are expected to take place during Japanese Prime Minister Fumio Kishida's visit to the White House on Wednesday. The Financial Times also reported that an upgraded security alliance between the US and Japan, the most significant since 1960, will likely be announced during the visit.

Last Wednesday, US Ambassador to Tokyo, Rahm Emanuel, wrote an opinion piece in The Wall Street Journal suggesting that Japan would become the first additional Pillar II partner. While his comment was received well by some within the US government who hope to expedite Japan's inclusion in Aukus, it has caused concern among others in Washington, London, Canberra, and Tokyo.

In addition to these developments, Washington will be hosting the first-ever US-Japan-Philippines trilateral summit on Thursday, further underlining the United States' commitment to strengthening alliances in the region.

China's concerns about Japan's potential inclusion in the Aukus security pact highlight the regional tensions in the Indo-Pacific, as major powers seek to shape their alliances and influence in the face of growing geopolitical competition.