Japarov has won almost 80 per cent of the vote in the Central Asian nation which is closely allied with Russia, preliminary results cited by Kyrgyzstan's Central Election Commission showed on Sunday, meaning there will be no run-off.

More than 80 per cent of voters have also supported a proposal to reform the constitution to give the president greater powers at parliament's expense, the commission said.

Violent protests which erupted last October sprung Japarov from jail to the prime minister's chair and culminated in him assuming the interim presidency before he ran for the full-time role.

Japarov, who was sentenced to a lengthy prison term for kidnapping a provincial governor as part of a protest, had his verdict quashed amid the October unrest and has outspent 16 presidential poll rivals by a wide margin.

Despite his nationalist stance - Japarov's first act as prime minister was to add ethnicity information to national ID cards - he has repeatedly pledged to maintain a close relationship with former Soviet overlord Moscow.

"Russia is our strategic partner," Japarov said after casting his ballot in a suburb of capital Bishkek, and urged all groups to accept the results in order to preserve stability.

Russia operates a military airbase in the mountainous nation and is the main destination for hundreds of thousands of Kyrgyz migrant labourers.

Neighbouring China is another key trade partner and investor in the impoverished and predominantly Muslim nation, whose economy has been battered by the coronavirus pandemic and the resulting disruptions to trade and travel.

Japarov's prison sentence stems from his campaign in the early 2010s to nationalise the giant Kumtor gold mine operated by Canada's Centerra Gold.

But after coming to power last year, he said that was no longer a goal and he would only seek to ensure profits are split fairly.

Japarov's campaign, which combined references to traditional symbols and values with promises such as doubling healthcare spending, struck a chord with voters, especially in rural areas.

Before toppling the government of President Sooronbai Jeenbekov in October, similar violent protests deposed presidents in 2010 and 2005.

"I voted against everyone because it makes no difference for ordinary people who is in charge, everyone lies to us," said Bakyt, a 52-year-old power engineer who only gave his first name.

Australian Associated Press