More than 2,100 soldiers were mobilized in the drill, part of a war game codenamed "Han Kuang (Han Glory) 21".

Around 200 army paratroopers, following simulated attacks by jet fighters, launched a mock airborne attack by the People's Liberation Army on the base in central Taiwan.

Taiwanese troops, flanked by Super Cobra attack helicopters and Kiowa scout helicopters, Avenger air defense missiles, tanks and armoured vehicles, fought back to surround the mock invaders.

"Despite a lack of external threat, the Chinese government has actively expanded its arms buildup, increased missile deployment and beefed up its missile projecting capability," Chen said after witnessing the war game.

China in March also enacted a controversial anti-secession law, which provides the legal basis for an invasion of the island, Chen said.

"The acts have sparked doubts of peace-loving countries about the motivation of Beijing's persistent arms build-up," he said.

Chen urged the international community to curb China's military rise. "If not, then all the members of the international community would have to jointly take the consequences," he said.

Last week the Pentagon released a report warning that China had deployed up to 730 ballistic missiles opposite the island. It said Beijing's defence build-up could tip the military balance against Taiwan and pose a credible threat to other countries in the region.

Chen called on the opposition to support a planned multi-billion-dollar arms package.

The bill authorising the package calls for the purchase of six PAC-3 Patriot anti-missile systems, eight conventional submarines and a fleet of submarine-hunting P-3C aircraft from the United States over a 15-year period.

In December the legislature killed the original bill, which was priced at 610.8 billion Taiwan dollars (19.33 billion US), with some opposition lawmakers saying Taiwan could not afford it.

Others said the equipment would be delivered too slowly to enable Taiwan to catch up with China's military build-up.

An amended package valued at 480 billion Taiwan dollars failed to pass the legislature's procedure committee, a necessary step before it can be heard in the full house.

Relations between China and Taiwan, which split in 1949 at the end of a civil war, have worsened since independence-leaning Chen was elected president in 2000, ending the nationalist Kuomintang's 51-year rule.

He was re-elected last year.

China has vowed to attack Taiwan should the island declare formal independence. The two sides split in 1949 at the end of a civil war.