Taiwan unveiled its first indigenous defense submarine, "Narwhal," on Thursday in the southern port city of Kaohsiung, in what the island's leader Tsai Ing-wen described as a milestone in "defense independence" amid cross-strait tensions.

Speaking at a ceremony, Tsai said in front of the naval vessel that the day will forever be remembered for the launch of the submarine designed and built by Taiwanese people. It will undergo testing at sea starting in October and is expected to be delivered to the navy by late 2024, according to local media reports.

Tsai said submarines are vital for the island's navy in terms of strategy and tactics to develop "asymmetric combat power," referring to the capability of a small power to focus on the weakest point of a bigger enemy, namely mainland China.

Taiwan's first indigenous submarine is unveiled at a ceremony in the southern port city of Kaohsiung on Sept. 28, 2023. (Kyodo)

In addition to procuring weapons from overseas, Taiwan must also implement defense independence so that the island's combat capabilities can be continuously updated and its defense capabilities more resilient, Tsai said.

Since Tsai took office in May 2016, she has been pushing a "design and build at home" policy for military airplanes, vessels and submarines.

The indigenous submarine project was launched in 2017 and made a major breakthrough in 2018 when the U.S. State Department allowed American manufacturers to sell submarine technology to Taiwan.

The Narwhal submarine, manufactured by Taiwan shipbuilder CSBC Corp., is about 70 meters long and in the class of 2,500-3,000 tons. The budget of NT$49.3 billion ($1.53 billion) has been allocated for the first sub.

Taiwan aims to domestically build another submarine by 2027, according to local media. It means the island will have a total of three combat-ready submarines by 2025 and four by 2027, including the two existing Chien Lung-class subs bought from the Netherlands in the 1980s.

Huang Shu-kuang, who is responsible for the building of subs, told Taiwan media the two new submarines to be built by 2027 will be deployed to defend the waters around Taiwan and the area from Suao in Yilan in Taiwan's northeast to Yonaguni Island in southern Japan's Okinawa Prefecture.

China the same day slammed Taiwan's ruling Democratic Progressive Party for squandering the island taxpayers' money to buy weapons. "Creating cross-strait antagonism and confrontation will only undermine peace and stability across the Taiwan Strait," Foreign Ministry spokeswoman Mao Ning said.

Communist-ruled China views the self-ruled democratic island as a renegade province to be united with the mainland, by force if necessary.

Chinese Defense Ministry spokesman Wu Qian also said the submarine project suggests Taiwan is trying to do something beyond its ability.

"No matter how many weapons the DPP authorities build or purchase, they cannot stop the reunification of the motherland, nor can they shake the People's Liberation Army's strong determination, firm will, and robust ability to defend national sovereignty and territorial integrity," Wu said.