TAIPEI, TAIWAN -- Taiwanese President Tsai Ing-wen said Sunday that the self-governing island's democracy remains under direct threat from rival China, underscoring her calls for closer ties with the U.S. and other allies.

Tsai was speaking at a televised debate against Han Kuo-yu of the main opposition Nationalist Party and veteran politician James Soong of the People's First Party. Elections for president and the legislature are set for Jan. 11. Most polls show Tsai leading in her quest for a second four-year term.

Tsai said she would preserve Taiwan's freedoms and way of life, but would make no changes to the constitution or the island's official name, the Republic of China, which moved its seat of government to Taipei, the island's capital, following the Communist Party's seizure of power on mainland China in 1949.

"Taiwan's most pressing challenge arises from China's expanding ambitions," Tsai said. "The situation in our region is ever-more complex and Taiwan's sovereignty -- its free, democratic way of life -- is under threat of being stripped away and undermined."

"We need to deepen and strengthen our international relations, and at present we are doing so in terms of economics and across the board with many countries," she said.

Tsai's governing Democratic Progressive Party currently holds a majority in the assembly, allowing her to pursue an agenda of economic reforms, partly intended to attract reinvestment from Taiwanese business groups based in China and elsewhere.

During the debate, Han furthered his claims of facing opposition from the mainstream media and accused Tsai's backers of corruption. He described China's threat to use military force to bring Taiwan under its control as an abstraction and defended his previous dealings with Chinese authorities as necessary to ensure Taiwan's economic future.

"Don't smear people. You love Taiwan? I love Taiwan also," Han said.

Soong, who commands a portion of the pro-China electorate, cast himself as a moderate who could bring political experience to the office.

Tsai has taken a lead in polls in recent months, partly in response to the crackdown on pro-democracy protests in Hong Kong. China governs the semi-autonomous city under a "one country, two systems" framework that it has also proposed for Taiwan, but which has been overwhelmingly rejected by the island's nearly 24 million people.