Taiwan on Wednesday welcomed the confirmation of its purchase of a fleet of advanced US attack helicopters, saying it would boost its defences even as it seeks improved ties with mainland China.

The US Department of Defense announced Tuesday that defence contractor Boeing acquired the contract to sell 30 Apache AH-64D Longbow helicopters to Taiwan, and that it was required to deliver them in 2014.

The deal "will certainly help beef up Taiwan's naval, anti-landing and ground-warfare capabilities," Defence Ministry spokesman Yu Sy Tue told AFP, adding that the deal was evidence of Taiwan's determination to defend itself.

Ties between Taipei and Beijing have improved markedly since Ma Ying-jeou of the China-friendly Kuomintang party was elected president in May 2008, promising to improve trade with and tourism from the mainland.

Beijing, which regards Taiwan as part of its territory, declines to renounce the use of force against the island, which has governed itself since the end of China's civil war in 1949.

In response, Taiwan has built up a defence force equipped with weapons acquired mostly from the United States, despite Washington switching diplomatic recognition from Taipei to Beijing in 1979.

The Apache agreement was signed by the government of former US president George W. Bush in 2008 in a deal that also includes a simulation AH-64D for maintenance, repair and training purposes.

In January, Washington announced a weapons package for Taiwan that includes Patriot missiles, Black Hawk helicopters and equipment for Taiwan's F-16 fleet, but no submarines or new fighter aircraft.

Beijing reacted angrily to that arms deal, saying it would cut military and security contacts with the United States.