Taiwan issued an order Sunday calling up thousands of reserve troops to participate in a huge drill aimed at testing the island's defence capabilities against a D-Day style attack by China.

The mobilised reservists will take part in "Han Kuang (Han Glory) No 28", a five-day drill beginning Monday that will play out a scenario in which the enemy attempts to invade the capital, defence ministry officials said.

Ties between Taiwan and its former rival China have improved drastically since Ma Ying-jeou of the China-friendly Kuomintang party came to power in 2008 promising to boost trade and tourism links.

But China still claims sovereignty over Taiwan, which has governed itself since 1949, and has vowed to get it back -- by force if necessary -- even though the island has ruled itself for more than 60 years.

The reservists were ordered to report by 8:00 am Monday (0000 GMT) for what is the biggest military war game of the year.