TAIPEI/TAINAN, Taiwan, Jan 13 (Reuters) - Polls opened on Saturday in Taiwan's presidential and parliamentary elections which China has framed as a choice between war and peace and are happening as Beijing ramps up pressure to get the island to accept its sovereignty.

Taiwan has been a democratic success story since holding its first direct presidential election in 1996, the culmination of decades of struggle against authoritarian rule and martial law.

The ruling Democratic Progressive Party (DPP), which champions Taiwan's separate identity and rejects China's territorial claims, is seeking a third term in office with its candidate, current Vice President Lai Ching-te.

Speaking to reporters in the southern city of Tainan before voting, Lai encouraged people to cast their ballots.

"Every vote is valued, as this is Taiwan's hard earned democracy," he said in brief remarks.

In the run up to the election, China repeatedly denounced Lai as a dangerous separatist and rebuffed repeated calls from him for talks. Lai says he is committed to preserving peace across the Taiwan Strait, and keep boosting the island's defences.

Taiwan's defence ministry said on Saturday morning it had again spotted Chinese balloons crossing the sensitive Taiwan Strait, one of which flew over Taiwan itself. The ministry has denounced as psychological warfare and threat to aviation safety the spate of balloons reported over the Strait in the past month.

Lai is facing two opponents for the presidency - Hou Yu-ih of Taiwan's largest opposition party the Kuomintang (KMT), and former Taipei mayor Ko Wen-je of the small Taiwan People's Party (TPP), only founded in 2019.

Hou wants to restart engagement beginning with people-to-people exchanges and has, like China, accused Lai of supporting Taiwan's formal independence. Lai says Hou is pro-Beijing, which Hou rejects.

Ko has won a passionate support base, especially among young voters, for focusing on bread and butter issues such as the high cost of housing. He also wants to re-engage China, but insists that cannot come at the expense of protecting Taiwan's democracy and way of life.

Ko told reporters after voting at a Taipei high school he was "calm" and had slept well the night before.

The parliamentary elections are equally important, especially if neither of the three parties are able to get a majority which might stymie the new president's ability to pass legislation and spending, especially for defence.

Polls are open for eight hours and close at 4 p.m. (0800 GMT), with ballot counting by hand starting almost at once. There is no electronic, absentee, proxy or early voting.

The result should be clear by late evening Saturday when the losers concede and the winner gives a victory speech.

President Tsai Ing-wen is constitutionally barred from standing again after two terms in office.

Photo from Reuters