Democratic Taiwan has seen a ramp-up in military and political pressures in recent years from Beijing, which considers the island its territory and has vowed to seize it one day -- by force if necessary.

Taipei's Ministry of National Defence reports near-daily warplane incursions by the Chinese military, which in the past year has carried out massive wargame exercises around Taiwan's waters.

On Thursday the ministry said that China's "Shandong Carrier Strike Group crossed the Bashi Channel today and entered the Western Pacific".

Taiwan's military has "monitored the situation and tasked appropriate forces to respond", it said.

Earlier in the day, the ministry said it had detected 15 Chinese warplanes crossing the median line bisecting the Taiwan Strait -- a 180-kilometre (110-mile) waterway separating the island from China -- between the hours of 6:00 am to 12:00 pm (2200 GMT Wednesday to 0400 GMT Thursday).

"The aircraft... conducted joint combat patrol with (People's Liberation Army Navy) vessels," it said in an announcement.

Taiwan's defence minister earlier this month said that China had stepped up "military intimidation" on the island by flying an increased number of warplanes around it.

The island detected a "recent high" of 103 Chinese warplanes in September, as well as nine navy ships.

The ministry had decried China's "military harassment", saying it could "lead to a sharp escalation in tension and worsen regional security".