That will more than half the time it currently takes because passengers have to change planes at a third territory, usually Hong Kong, a source close to the Civil Aeronautics Administration said yesterday.

P.K. Chiang, chairman of the Straits Exchange Foundation, is expected to sign an agreement with his Chinese counterpart Chen Yunlin of the Association for Relations across the Taiwan Strait on June 14 in Beijing to get the charter flights at weekends started.

Another agreement will also be inked to let tourists come from China to visit Taiwan at the same time.

Currently, only Chinese residents abroad are allowed to visit Taiwan.

There will be no "danger" to Taiwan's national security after the direct flights begin, the source said. "Because the previous administration did not want to set the direct flight link in place," he added, "the military used to say Taiwan's air security would be at risk."

The Ministry of National Defense kept mum on whether the air routes to be opened may pose a threat to the national security of Taiwan.

At least four new routes will be opened. Ground-to-air missiles are deployed at Tamsui, Shanchi and Wanli to safeguard Taiwan's territorial air, and the new flights have to be so routed that they do not seriously interfere with the air defense deployment.