Taiwan has carried out the maiden torpedo test-firing from its first domestically developed submarine, a major milestone in a project aimed at strengthening deterrence against the Chinese navy and protecting vital sea lanes in the event of war.

Taiwan, which China claims as its own territory, has made the indigenous submarine program ?a ?key part of an ambitious project to modernize its armed forces as Beijing stages almost daily military exercises to assert its sovereignty claims.

The submarine program has drawn on expertise and technology from several countries, including the United States and the U.K., a breakthrough for diplomatically isolated Taiwan, whose government rejects Beijing¡¯s territorial claims.

Taiwan¡¯s CSBC, which is leading construction of what is eventually planne to be eight submarines, said in a statement Thursday that the first ship, named the Narwhal, had carried out its first torpedo test the day before.

The test verified the combat system¡¯s operational capabilities in ?terms of detection and tracking, fire control, launch, and torpedo guidance, it said.

In January, the submarine carried out its first underwater sea trial.

Taiwan has said it hopes to ?deploy at least two such domestically developed submarines by 2027, and possibly equip later models with missiles.

The first submarine, with a price tag of 49.36 billion New Taiwan dollars ($1.57 billion), will use a combat system by Lockheed Martin and carry U.S.-made Mark 48 heavyweight torpedoes.

The CSBC statement did not say what kind of torpedoes were test-fired.

The Narwhal had been due to be delivered to the navy in 2024, joining two existing submarines purchased from the Netherlands in the 1980s, but the program has been hit with delays.

Taiwan¡¯s armed forces are dwarfed by those of China, which has three operational aircraft carriers and several nuclear-powered ballistic missile submarines, and is developing stealth fighter jets.