But Wu defended new President Chen Shui-bian's call for a "decisive battle offshore" if China attacked, according to the Chinese-language China Times.

Wu said the idea Chen raised on June 20 aimed to "solve the issue in the Taiwan Strait" rather than "bring it to the island."

"It is by no means a perception of offensive strategy," Wu said, dismissing speculation that the new government was altering its defensive strategy against China.

"The armed forces will not adopt any offensive military action unless the Chinese communists launch an attack," he said.

"That means we will continue to stick to the policy, under which we would not fire the first shot and would rather take the first strike (from the mainland)," he added.

But Wu appealed for the establishment of a deterrent to dissuade any attempt by China to take the island by force.

"With such a deterrent, the enemy would be aware that they have to pay dearly if they dare to attack us," he said.

He said the defense ministry was giving priority to the acquisition of submarines and destroyers armed with Aegis weapons system.

"Given the ongoing international situation, buying or building submarines is very difficult ... but acquiring submarines was always given priority," Wu said.

Taiwan has four submarines in service, among them two Dutch-built Swordfish and two outdated US-built submarines that have virtually no combat capability.

Wu hailed the Aegis class destroyers for their superb capability in defending against ballistic missiles, cruisers and ship-to-ship missiles.

But Washington in April decided to postpone a decision on the sale of four Aegis destroyers to Taiwan for fear of harming ties with Beijing.

In December former vice president Lien Chan said: "In order to deter the enemy from invading Taiwan, we have to develop reliable deterrents and beef up the second-strike capability."

He added that "the naval and air force must be strengthened ... and long-range ground-to-ground missiles developed."

Taiwan secretly launched the "Tien Ma (Sky Horse)" missile program in the 1980s to develop ground-to-ground missiles with a range of 1,000 kilometers (620 miles).

Unconfirmed reports said the program was called off under pressure from Washington.

Beijing, which views Taiwan as part of its territory awaiting reunification, has vowed to use force to retake the island if it should declare independence, be invaded by another country or indefinitely prolong reunification.