Taiwan on Wednesday retired two patrol boats, the navy's first vessels armed with ship-to-ship missiles, that were hailed as "critical" to safeguarding the island, officials said.

Hundreds of former and active soldiers who had served on board the 240-tonne Lung Chiang and Sui Chiang bid farewell to the ships at a ceremony in southern Kaohsiung city, the navy said.

Vice Admiral Chiang Lung-an said the ships "have played a critical role in safeguarding Taiwan over the past 30 years".

The US-made Lung Chiang joined Taiwan's navy in 1978, while the Taiwan-built Sui Chiang came three years later in 1981. Each was armed with four homemade "Hsiung Feng I" (Brave Wind I) anti-ship missiles.

Earlier this year, Taiwan's navy put a squadron of 10 guided-missile boats into service featuring what was described as "stealth" technologies as it looked to boost its defences amid Beijing's military buildup.

Tensions in the Taiwan Strait have eased since President Ma Ying-jeou of the China-friendly Kuomintang party came to power in 2008, pledging to boost trade links and allowing more Chinese tourists to visit the island.

But Beijing considers Taiwan part of its territory awaiting reunification, by force if necessary.

The island has governed itself since its split with mainland China in 1949 at the end of a civil war.