Before an audience that included President Ma Ying-jeou, five out of 19 missiles failed to hit their targets at the Chiupeng military base in the island's south.

"It's within our predictions, but of course there's room for improvement," said air force Lieutenant General Pan Kung-hsiao, when asked to comment about the missiles that went astray.

Ma, however, was less forgiving, telling journalists that the military should get to the bottom of the failures.

"I'm not very satisfied," Ma said. "Some missiles missed the targets, and we need to review whether these errors were mechanical or human. We also need to hold more drills to boost military capabilities."

The missile drill at the normally tightly guarded base was the largest open to the media since Ma assumed power in 2008.

It was meant to signal Taiwan's defence capabilities to the island's own public just days after China unveiled the J-20, an aircraft that uses stealth technology to avoid radar detection, according to analysts.

"Taiwan wants to reassure its people at a time when China keeps developing advanced weapons such as the J-20," said Edward Chen, a political scientist at Tamkang University's Graduate Institute of American Studies.

The drill also came on the same day that Chinese President Hu Jintao was to leave for a state visit to the United States, with Taiwan likely to be on the agenda.

China and Taiwan have been governed separately since the end of a civil war in 1949, but Beijing considers the island part of its territory, and has never renounced the possible use of force to get it back.

Among the weapon systems tested Tuesday were home-made Tien Kung, or "Sky Bow" surface-to-air missiles, French-made Mica and Magic air-to-air missiles and US-made Hawk surface-to-air missiles.

Military authorities said the drill was launched only after they were certain that no Chinese spy ships were near the coastal missile base aiming to collect information.