The Philippines' new president has said he "will go to the extreme" in his battle to end crime within six months, but won't become a dictator.

Rodrigo Duterte said in a speech to policemen on Friday that he is not afraid of being impeached by Congress while battling crime and assured police he will protect them if they kill a large number of people while cracking down on lawlessness.

Duterte was inaugurated Thursday. On Friday, he witnessed the official appointment of his national police and military chiefs and ordered them to combine their forces to fight criminals.

Duterte says he will pursue peace talks with communist and Muslim rebels, and announced he will meet next week with the Moro Islamic Liberation Front, the largest Muslim rebel group.