Taiwan's main opposition Nationalist Party (KMT) on Sunday officially nominated sitting Kaohsiung Mayor Han Kuo-yu as its candidate for next year's presidential election.

Speaking at a stadium in Banqiao, New Taipei City, after receiving the nomination, Han appealed to the public at large to help the party win in January.

"Only the KMT can protect the Republic of China (Taiwan's official name) and improve people's livelihoods," Han told those assembled at the party's national congress, which met Sunday to finalize his nomination.

Apart from criticizing President Tsai Ing-wen's performance over the past three years, Han vowed to make Taiwan safer and enable people to make more money if elected.

Saying the 2020 elections will determine the island's fate, Han urged the public not to "ask what your country can do for you, but ask what political party or politician you can elect for the country."

The KMT announced earlier this month that Han won its closely fought presidential primary, which was based on the results of public opinion and phone surveys. He beat his closest challenger Terry Gou, the billionaire founder of iPhone assembler Foxconn, by a comfortable margin.

China-friendly Han will run against the incumbent Tsai of the independence-leaning party Democratic Progressive Party, among other candidates.

Han, the former head of Taipei's wholesale fruit and vegetable markets, took the political world by surprise with his shock victory last November in the Kaohsiung mayoral election.

Some attributed the result to "outside forces," meaning China, while others believed Han did not so much win as the Democratic Progressive Party candidate lost.

Others chalked up Han's election victory in the DPP heartland to a combination of personal charisma and a skillfully crafted campaign strategy.

(Kaohsiung Mayor Han Kuo-yu (L) and KMT Chairman Wu Den-yih)

Han has said himself that he was merely a conduit for public frustration over the DPP's neglect of Taiwan's South, which has long suffered from poor economic prospects while the North boomed.

KMT Chairman Wu Den-yih told the national congress that returning to power in January is not for the interests of the KMT or Han, but for those of Taiwan and the next generation.

He set the goal of winning the presidential election and securing at least half of the seats up for grabs in the legislative election, which will be held concurrently in January.

Some worry that fissures caused by the presidential primary might divide the party.

All eyes are on Gou and former legislative speaker Wan Jin-ping.

Gou has been evasive about what his next move will be. Some in the party worry that he might run for president as an independent.

Wang, who had taken himself out of the primary, has vowed to "continue the race," without elaborating. He has dismissed speculation of running as an independent.

In addition to finalizing Han's nomination, congress members also agreed to amend the party charter to decouple the position of the party chair from the presidency, allowing Wu to stay on the job if the KMT wins the presidential poll.