President Rodrigo Duterte said he has been pushing for a federal form of government to avoid war in Mindanao and not because he wants to perpetuate himself in power.

Duterte reiterated he could step down from office even before his term ends in 2022 if a new system of government has been put in place.

"Federal system would be the ideal setup," he said in a speech in Davao City on Thursday.

But Duterte added if others do not like the shift to federal system from presidential, "we have to make concession."

He said the Philippines could have a "hybrid" form of government, similar to Hong Kong and China.

Hong Kong, a special administrative region of China, is exercising autonomy.

Duterte said he wants federalism to prevent war in Mindanao.

"You know why...because we want to avoid war. We will surely have chaos here in Mindanao. If you don't give it to them, there will be trouble. I'm telling you as your president that we will have chaos. We're sorry here in Mindanao," Duterte said.

"That is my only concern. It's not because I want to perpetuate in power," he said.

He noted he has been in government for 23 years.

Prior to becoming president, Duterte was the mayor of Davao City. He also became a congressman and vice mayor of the city.

"That's why if you want, a day or two days before (my term ends), I will step down. If the federal system is approved by 2019, 2020, I assure you, I will step down if it calls for a new set up and a new president," he said. Celerina Monte/DMS