Philippines’ President Rodrigo Duterte maintains the killings he claimed he committed while mayor of a southern city were part of legitimate operations against drug dealers.

Speaking to Filipino journalists travelling with him in Singapore, Mr Duterte said he sometimes cruised the streets on a motorbike looking for “encounters to kill”.

He says he killed three men during a hostage-taking incident in Davao City, where he was mayor for more than 20 years.

Supporters rally around Rodrigo Duterte at his final campaign rally. Photo: AAP

“It was not because I was walking around that I killed,” he said.

“It was actually an event that was covered by the TV … I said I killed about three of them.

“I didn’t really know how many bullets from my gun went through inside their bodies.”

The firebrand leader told a gathering of business leaders at the presidential palace on Monday that he had “personally” killed criminals and that he was prowling the city’s streets on a big bike.

Senators have warned Mr Duterte risks impeachment because of his statements about personally killing criminals in Davao.

We do not need American money: Duterte

Mr Duterte has told the United States to prepare for the eventual repeal of a military deal that allows Washington to deploy troops and equipment for exercises in the country.

Duterte also said the Philippines can survive “without American money” after a US aid agency put on hold a decision to fund anti-poverty programs in the country.

“We do not need you,” Duterte said in a news conference after arriving from visits to Cambodia and Singapore.

“Prepare to leave the Philippines. Prepare for the eventual repeal or abrogation of the VFA.”

With AAP and ABC