Trump’s admiration of South Asian strongmen breaks with diplomatic precedent at a time when his administration is challenging traditional alliances.
The Philippine leadership was wary of U.S. military activity on its territory.
Over 2 million tourists visit the island each year, bringing in around $1 billion in revenue.
"One fight there, another here—at the age of 16, I killed someone. A person, really," he said.
It is not the first time the Philippines president has referenced cannibalism.
Elected a year ago, one of Philippine president's campaign pledges was to rid the country of "sons of bitches" drug users and dealers.
One year after becoming president, Duterte has managed to insult many international figures.
"He signs papers, he reads, he consults, he's actually very busy."
Farhana Maute is the matriarch of the Maute group, currently waging war against the army in Marawi City, Philippines.
The conflict in the southern Philippines has been raging for more than a month, despite President Duterte's assurances it would be over in three days.
"The school area is again safe."
Duterte had previously warned the international community from "meddling" in the Philippines' affairs.
They fear that new groups will join the conflict after Eid al-Fitr.
The Maute Group and other rebels are targeting Christians in the fight to takeover the city.
The war has lasted for 14 days in the southern island of Mindanao.
"I can end this war in 24 hours. All I have to do is to bomb the whole place," Philippines President Rodrigo Duterte said.
Philippine authorities say there's no evidence of terrorism in the attack which left 36 dead and dozens wounded.
The army has used airstrikes and street combat, yet still the Maute Group Islamist militants fight on.
The army has used airstrikes and street combat to try and force out the Maute group militants who took hold of the city a week ago.
Attached to one of the bodies was a sign that said "Munafik", meaning "traitor."
"We have a lot of firepower over there," Trump said to Duterte, before revealing that firepower included two nuclear submarines.
Malaysia, the Philippines, Vietnam, Japan, and China all claim parts of the South China Sea.
73 percent of respondents said they were concerned that they or someone they know will be a victim of the war on drugs.
The Philippines president has abandoned his plan to plant a flag on the Spratlys.