Taiwan is not seeing any signs of large-scale Chinese military activity before elections next month but is keeping a close watch on China, the island's defence ministry said on Tuesday.

Taiwan's Jan. 13 presidential and parliamentary election will shape the Chinese-claimed island's relations with Beijing, which has over the past four years ramped up military pressure to assert its sovereignty claims.

As the election approaches Taiwan has been reporting Chinese fighter jets and warships around the island, as well as balloons crossing the sensitive Taiwan Strait, though the military says they are most likely for weather monitoring purposes.

"So far we haven't seen signs they're making big moves, but nothing today doesn't mean there won't be something tomorrow or the day after tomorrow," Taiwan defence ministry spokesperson Sun Li-fang told reporters in Taipei.

"We are watching all the time," he added.

China has not hidden its dislike of the presidential frontrunner Lai Ching-te from the ruling Democratic Progressive Party, regularly denouncing him as a separatist and warning any moves towards Taiwan's formal independence means war.

Lai has repeatedly offered talks with China that have been rebuffed. He says Taiwan is already an independent country called the Republic of China, its formal name.

The defeated republican government fled to Taiwan in 1949 after losing a civil war with Mao Zedong's communists who declared the People's Republic of China.

Taiwan's defence ministry gives a daily update on Chinese military activities near the island, including how many aircraft it has detected.

Over the past year and a half China has staged two major rounds of war games near Taiwan.