China expressed strong opposition Thursday to Taiwan's bid to participate in the Trans-Pacific Partnership free trade deal, repeating its mantra that the self-ruled island is an "inalienable part of China."

The Communist-led government's remarks indicated it will make every effort to prevent Taiwan from joining the TPP under its "one-China policy," cementing speculation that tensions between the mainland and the democratic island will intensify over membership.

"The one-China principle is a recognized norm of international relations and a general consensus of the international community," Chinese Foreign Ministry spokesman Zhao Lijian told reporters.

The mainland "resolutely opposes Taiwan's accession to any official agreements and organizations," he added, a day after the island submitted an application to join the trade pact, from which the United States withdrew in January 2017.

The leadership of Chinese President Xi Jinping filed its bid for membership in the TPP, formally known as the Comprehensive and Progressive Agreement for Trans-Pacific Partnership, last week in an apparent attempt to bolster its economic clout in the region.

Late last year, China also signed the world's biggest free trade deal, called the Regional Comprehensive Economic Partnership or RCEP, with 14 other Asia-Pacific countries -- Australia, Japan, New Zealand, South Korea and the 10 Association of Southeast Asian Nations members.

While Japan has welcomed Taiwan's application to take part in the TPP, some of the 11 member countries such as Singapore and Malaysia, whose economies have relied on China's huge market, have voiced hope for Beijing's participation in the pact.

It is still uncertain whether both or either China and Taiwan will be allowed to enter the TPP, given that the unanimous approval of all 11 members is required to join the deal.

A source close to the matter said Beijing's bid to join the TPP may just be intended to thwart Taiwan's ambition to become a member of the pact.

The TPP is designed to cut tariffs on agricultural and industrial products, ease investment restrictions and enhance intellectual property protection, with an eye on improving economic integration among participating nations.

The so-called high-quality TPP, so far composed of Australia, Brunei, Canada, Chile, Japan, Malaysia, Mexico, New Zealand, Peru, Singapore and Vietnam, is widely seen as being aimed at countering China's growing economic influence.

Many TPP members, including Japan, have been at odds with China over technology transfer, intellectual property protection, market openness and transparency as well as other trade issues, diplomatic sources said.

Meanwhile, the administration of U.S. President Joe Biden, who prioritizes multilateralism in diplomacy, has remained cautious about the country returning to the treaty.

In 2017, then U.S. President Donald Trump, Biden's predecessor, pulled the United States out of the TPP by pursuing trade policies widely viewed as protectionist under his "America First" agenda. Washington has also not participated in the RCEP.

China and Taiwan have been separately governed since they split in 1949 as a result of a civil war. Their relations have deteriorated since independence-leaning Tsai Ing-wen became Taiwan's president in 2016. The mainland considers the island as a renegade province.

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