Beijing considers self-ruled, democratic Taiwan a part of its territory, to be taken one day, by force if necessary, and the island lives under the constant fear of a Chinese invasion.

Under President Xi Jinping, China's sabre-rattling has intensified in recent years, and Russia's invasion of Ukraine deepened worries in Taiwan that Beijing might move similarly to annex the island.

China's "intimidation and threats against Taiwan are getting more obvious", President Tsai Ing-wen told a press conference.

"No one wants war... but my fellow countrymen, peace will not fall from the sky."

"The current four-month military service is not enough to meet the fast and ever-changing situation," she added.

"We have decided to restore the one-year military service from 2024."

The extended requirement will apply to men born after January 1, 2005, Tsai said.

Mandatory service used to be deeply unpopular in Taiwan -- once a brutal military dictatorship that has since morphed into a progressive democracy.

Its previous government had reduced compulsory military service from one year to four months with the aim of creating a mainly volunteer force.

But recent polling showed more than three-quarters of the Taiwanese public now believes that is too short.

The military has also struggled to recruit and retain full-time personnel because of low financial incentives.

Tsai described the extension as "an extremely difficult decision... to ensure the democratic way of life for our future generations".

- Outgunned -

The prospect of a Chinese invasion has increasingly worried Western nations and many of China's neighbours.

Xi, China's most authoritarian leader in decades, has made clear that what he calls the "reunification" of Taiwan cannot be passed on to future generations.

Taiwan and China split at the end of the Chinese Civil War in 1949, and Tsai has said becoming a part of China is not acceptable to the people of the island.

Taiwan is a mountainous island and would present a formidable challenge to an invading force, but it is massively outgunned with 89,000 ground forces compared with China's one million, according to a Pentagon estimate released last month.

Beijing also has a huge advantage in military equipment.

Taiwan has stepped up reservist training and increased its purchases of warplanes and anti-ship missiles to bolster its defences. But experts have said that is not enough.

The military service announcement on Tuesday came two days after Chinese military exercises near Taiwan, which were held in response to what Beijing described as "provocations" and "collusion" between Washington and Taipei.