MANILA - President Rodrigo Duterte on Friday said he will step down if the country has shifted into a successful federal government by 2020.

"Mag-resign na lang ako. Sabihan nila ako diktador anak ng... If they can perfect that federal set-up in 2020 I will step down," Duterte said during a speech at the Manila Times' 7th Business Forum in Davao City.

Duterte also denied favoring the military so he could be a dictator.

• Duterte: I have to be a dictator

"'Bakit mahilig ka sa military? Maybe you want to ingratiate yourself?' Why should I? When there was war, I was with them. During the height of Marawi siege, I landed on the main battle area and and I took off at 8 at night dalawang beses," he said.

"Bakit ako magpalakas sa military? Dictator?" he said."Nobody but nobody should be a dictator in this country because the military will not allow it. It is not allowed under the Constitution. If I die, see to it that the rule of succession in the Constitution will be followed."

The President also took a swipe at ICC Prosecutor Fatou Bensouda, who announced on Thursday that she will open a preliminary examination into the crimes committed by the government in its anti-drug campaign.

• ICC prosecutor seeks PH gov't cooperation on crimes examination

"This girl, this prosecutor ako pa ang inuna. Sabi ko file the case kasi I want to cross-examine you. Ako mismo because the treaty forms part of the laws of the land. Certainly, a treaty cannot be more powerful than a Constitution," he said.

"I respect you as a woman but as a lawyer... do not go in into that kind of adventure, it’s a messy one. I don’t even rate myself as good, ano lang, fair. You will get your comeuppance."

Duterte earlier said he is ready to face trial.

• Duterte unfazed by ICC review of drug war

He also slammed Sen. Antonio Trillanes IV, who filed a supplemental complaint against him before the ICC.

• Alejano, Trillanes file supplemental complaint vs Duterte at ICC

"Trillanes nagsasayaw-sayaw. Mga walang alam eh. Yan ang mahirap, hungry for power, attention. He’s one guy na nagmutiny p******* sikat pa ngayon. If you argue with stupid people, there’s no cure for stupidity. So the best way hayaan mo na yan," he said.