Beijing claims the self-ruled island as part of its territory, and has said it will not renounce the use of force to bring it under its control.

China has intensified pressure on the democratic island in recent years, and has staged three rounds of major military drills since President Lai Ching-te came to power in May.

The last of these earlier this month were the largest in years according to Taiwanese officials, although Beijing has not officially confirmed the manoeuvres.

"Chinese people on both sides of the Taiwan Strait are one family. No one can sever our blood ties, and no one can stop the historical trend of the reunification of the motherland," Xi said in a speech broadcast on state media.

Xi's comments come just weeks before Donald Trump takes office in the United States.

Taiwan is a key point of contention between Beijing and Washington, which does not officially recognise Taiwan diplomatically but is its strategic ally and largest supplier of weapons.

The US-China relationship may sour further after Trump is inaugurated on January 20, with the president-elect vowing more tariffs to punish what he calls unfair trade practices by China.

Beijing denies the allegations.