Incoming Philippines president Rodrigo Duterte repeated his campaign promises in the first nationally televised address after winning the presidency in the May 9 elections.

The tough-talking, unorthodox politician monotonously repeated he will kill criminals but also said he is determined to re-impose the death penalty and initiate a move for the amendment of the constitution.

Duterte, who campaigned on a populist anti-crime, anti-poverty plank, also said he will induct Communist rebels in his cabinet.

The 70-year-old mayor of the southern city of Davao said he would offer cabinet portfolios such as environment and natural resources, agrarian reform, social welfare and labour to the communist rebels.

"They are the most vigilant group in the Philippines about labor so they would get it," the presumptive president said.

He also repeated the campaign promise to re-introduce capital punishment for heinous crimes as part of his plan to improve law and order. Philippines had suspended capital punishment in 2006.

Duterte said criminals convicted of murder and rape will have to face death by hanging. "After the first hanging, there will be another ceremony for the second time until the head is completely severed from the body," Duterte said.

Another priority for the incoming president is to initiate legislation to switch to a federal form of government. Duterte has campaigned for the federal system saying it will better represent the diversity in the country and offer more power and resources to far flung regions.

He also gave a stern warning to corrupt police officers, saying they should end their ways or else prepare to be sent off to fight the Abu Sayyaf militants.

"And if you are taken hostage there, say your `Our Fathers' because I will never, never pay anything to retrieve you," Duterte added.