Philippines President Rodrigo Duterte launched into a series of personal attacks against US President Barack Obama during a press conference on Monday, after the Obama administration challenged the Philippines tough anti-drug policies.

Incensed by the US President’s plans to pressure him to change course, Duterte exploded on air, calling Obama a “son of a whore” in response to a reporter’s question on the issue.

"Who does he think he is? I am no American puppet. I am the president of a sovereign state, and we have long ceased to be a colony. I do not have a master except the Filipino people. You must be respectful. Do not just throw away questions and statements.”

After speaking in English, Duterte then switched to Filipino, and directly addressed President Obama.

“You son of a whore, I will swear at you.”

Duterte then resumed in English, pledging that the “campaign against drugs will continue.”

“Plenty will be killed until the last pusher is out of the streets. Until the drug manufacturer is killed, we will continue, and I will continue. And I don’t give a s*** about anybody observing my behavior. Nobody has the right to lecture me.”

When asked about the incident, President Obama downplayed the comments.

“Clearly he’s a colorful guy.”

Following President Duterte’s comments, the White House cancelled talks between Obama and his Filipino counterpart.

On Tuesday a spokesman for Duterte issued a statement regretting that the “strong comments” had “come across as a personal attack on the US president.”

“We look forward to ironing out differences arising out of national priorities and perceptions, and working in mutually responsible ways for both countries.”