Self-ruled democratic Taiwan has watched the Ukraine situation closely, as China claims sovereignty over the island and has vowed to seize it one day -- by force if necessary.

Beijing has ramped up military, diplomatic and economic pressure on Taiwan since President Tsai Ing-wen came to power in 2016, as she rejects the stance that the island is Chinese territory.

"Our government condemns Russia's violation of Ukraine's sovereignty... and urges all parties to continue to resolve the disputes through peaceful and rational means," Tsai said.

She described Taiwan and Ukraine as "fundamentally different in terms of geostrategy, geographical environment, and the importance of international supply chains," referring to the island's status as a major plank in the global economy, especially semiconductors.

"However, in the face of external forces attempting to manipulate the situation in Ukraine and affect the morale in Taiwan's society, all government units must be more vigilant against cognitive warfare."

Taiwan's defence ministry said last year that China has launched a disinformation campaign aimed at seizing the island "without a fight".

Tsai on Wednesday also told national security and military units to remain vigilant and step up surveillance of military activities around Taiwan.

The final quarter of 2021 saw a massive spike in incursions by Chinese warplanes into Taiwan's air defence identification zone.

Last year, Taiwan recorded 969 such incursions, according to a database compiled by AFP -- more than double the roughly 380 in 2020.

Beijing has trod a cautious line on Ukraine but also offered growing support to Russian President Vladimir Putin.

The two powers signed a joint statement this month, agreeing on multiple foreign policy goals including no further expansion of NATO and that Taiwan is an "inalienable part of China".

Chinese officials have also repeatedly sided with Russia in blaming the West for the tensions over Ukraine, accusing them of a "Cold War mentality" while describing Moscow's security concerns as "reasonable".