President-elect Rodrigo Duterte has vowed to overhaul the Philippines' system of government to devolve power from Manila to long-neglected provinces, and pursue a relentless crackdown on crime and corruption.

In a news conference, spokesman Peter Lavina said Mr Duterte would press for a shift from a unitary to a federal parliamentary form of government, which would lead to the formation of semi-autonomous regions that would have more authority over their budgets.

Mr Duterte would seek a national consensus on revising the Constitution - an often divisive issue - to pursue his government overhaul agenda although he has yet to fully articulate his plans, said Mr Lavina.

In interviews late on Monday, Mr Duterte also said he would push through a central plank of his platform - ending crime across the nation within six months and eliminating corruption.

He told reporters that he would take a direct hand in running the police force. He warned crooked cops: "If you are a policeman and stick to your racket, choose: either you kill me or I kill you."

Over his more than 20 years as mayor, Mr Duterte made once-lawless Davao one of the country's safest places. Human rights advocates said Mr Duterte managed to do this by using "death squads" held responsible for killing over 1,000 people. Mr Duterte himself has admitted participating in summary executions.

But police chief Ricardo Marquez said he does not expect Mr Duterte to go to such lengths. "He is a lawyer, a prosecutor. As president, I don't think that will happen," he said.

Mr Duterte's victory has not been confirmed, but an unofficial vote count by an election watchdog showed he had a huge lead over his two closest rivals, former interior minister Mar Roxas, 58, and Senator Grace Poe, 47, both of whom conceded defeat.

As at 11pm yesterday, Mr Duterte had 15.7 million votes, well ahead of Mr Roxas' 9.5 million and Ms Poe's 8.8 million. It is not clear when Mr Duterte's victory will be officially declared, but he is expected to take office on June 30.

Financial markets rebounded as Mr Duterte claimed victory. Stocks ended 2.6 per cent higher after falling more than 5 per cent over the past six weeks, as traders were concerned about Mr Duterte's economic plans. The peso gained against the dollar, ending the day at 46.75 against the greenback, from 47.09 last Friday.

"It's a fresh start for all," Philippine Stock Exchange president Hans Sicat told reporters.

Voters also chose the vice-president and senators. Eight-division boxing champion Manny Pacquiao was among the candidates assured of a Senate seat.

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