Beijing, which considers Taiwan a breakaway province, has renewed warnings to Taipei not to push for its independence.

China's policy is peaceful reunification, but China never promises to give up using force

Zhang Qiyue, Chinese Foreign Ministry

Newspapers on Thursday proclaimed the military's strength and willingness to invade the island if necessary.

Mr Chen, who was elected president in March, is deeply distrusted by Beijing because of his past support for independence.

China has issued warnings since Chen won the election in March

China's army newspaper, People's Liberation Daily, ran photographs of a mock invasion as well as pictures of missile launchers.

A banner by a photograph read: "Taiwan Independence Means War".

The photographs were from recent military exercises in the Nanjing area, which faces Taiwan.

On Wednesday, the official Xinhua news agency warned Taiwan of "disaster" if it did not accept the "One China" principle, which calls for reunification.

'Don't bully us'

In Taiwan, Mr Chen urged China to behave reasonably and not to use its strength to bully the island.

"Taiwan may be small but the truth is with us," he added. "We would like to talk with the mainland reasonably."

He said the island was "free, a democracy and respects human rights".

Mr Chen's plea came as the Taiwanese military prepared for a state of "heightened alertness".

An official said the defence ministry would monitor the movements of the Chinese military.

Fine line

Mr Chen has walked a fine line since winning the election on 18 March, which ended five decades of Nationalist rule.

Taiwan's honour guard captain inspects soldiers practicising for the inauguration

His inauguration speech on Saturday - when he will outline foreign policy towards China - will be closely watched.

But he has said he will not make provocative comments.

Mr Chen replaces Lee Teng-hui, who pushed democracy in his 12-year rule but was also blamed for increasing tensions with China.

In a speech marking his departure, he pointed to the need for national dignity and security as pre-requisites for improved relations with Beijing.

He angered China last year with his call for their relations to be based on an equal or state-to-state basis.

Taiwan's cabinet resigned on Thursday ahead of Mr Chen's inauguration.