TAIPEI (BLOOMBERG) - Taiwan's President said unrest in Hong Kong showed Beijing's "failure" in governing the city, and vowed to defend her democratically run island's sovereignty.

President Tsai Ing-wen said in her National Day address on Thursday (Oct 10) that Taiwan faced "unprecedented change" in the world and affirmed her commitment to fight for its survival, amid a threat from Beijing that has included recent efforts to isolate Taipei diplomatically.

"When democracy is under threat, we need to stand up to guard it. Being a president, I need to guard sovereignty, to maintain Taiwan's survival," she said.

"China uses 'one country, two systems' to threaten Taiwan and challenge regional stability. Hong Kong is approaching disorder because of the failure of 'one country, two systems'."

Coming three months before Taiwanese voters go to the polls, the multiple battles Beijing is fighting - from halting broadcasts of some United States National Basketball Association games to a protracted trade war with President Donald Trump and pro-democracy protests in Hong Kong - appear to be boosting Ms Tsai's hopes of re-election in January.

Ms Tsai enjoys a more then 13 percentage point lead over her main rival, Mr Han Kuo-yu of the opposition Kuomintang, according to a poll published in the Apple Daily newspaper on Tuesday.

Taiwan has been one of the strongest sources of overseas support for the Hong Kong protesters, amid growing international condemnation of aggressive tactics used by city leader Carrie Lam's Beijing-backed government.

Beijing's success in persuading two of Taiwan's diplomatic allies to switch recognition to China in the last month - the Solomon Islands and Kiribati - leaves Taipei with just 15 such partners worldwide.

But it also threatens to backfire as Taiwan's presidential election draws closer, with US and Australian concerns about China's growing footprint in the Pacific strengthening Ms Tsai's argument that Beijing poses a threat to Taiwan and regional order.

While the People's Republic has never controlled Taiwan, it claims the separately ruled island as part of its territory, a claim Ms Tsai's Democratic Progressive Party rejects.