Taiwan’s new opposition leader took office on Saturday, warning of the risk of war with China and pledging to open a new era of peace with Beijing.

Former lawmaker Cheng Li-wun takes the reins of the largest opposition party, the Kuomintang (KMT), at a time of rising military and political tension with Beijing, which views the democratically-governed island as its own territory.

"This is the worst of times. The Taiwan Strait faces grave military danger and the world is watching closely," she told party members in a speech at an indoor high school stadium in Taipei. "Taiwan's security faces the constant threat of war."

While the KMT traditionally espouses close relations with Beijing, Taiwan's government, led by the Democratic Progressive Party (DPP), strongly objects to China's sovereignty claims.

Cheng, 55, has already signalled a swing towards even closer ties with Beijing than her urbane, internationalist-minded predecessor Eric Chu, who did not visit China during his term as chairman that began in 2021.

Chinese President Xi Jinping swiftly sent congratulations after her election last month, calling for efforts to advance "reunification" in a message to her.

Some Chinese internet users refer to Cheng as the "reunification goddess", though she said this week she had been given many monikers online, adding, "If they are wrong or untrue, just laugh it off."

The KMT's new Deputy Chairman Hsiao Hsu-tsen visited China this week and met Song Tao, head of China's Taiwan Affairs Office.

Cheng did not give any details of her policy towards China in her maiden speech as party leader, nor say whether she would visit, instead saying she would work for peace.

"The KMT will definitely be the party that opens a new era of cross-Strait peace and leads Taiwan forward," she said.

Cheng also opposes higher defence spending, a key policy of President Lai Ching-te's administration. The spending has strong US backing.

While the KMT lost the presidential election last year, the party and its ally the small Taiwan People's Party together hold the most seats in parliament, creating a headache for the ruling DPP in trying to pass the budget and other legislation.

One of Cheng's first tasks will be preparing for mayoral and local elections late next year. While mostly focusing on domestic issues, these will provide an important gauge of support ahead of the 2028 presidential vote.