Obama cancels meeting after Philippine Prez calls him "son of a whore"

United States President Barack Obama has cancelled a meeting with his Philippine counterpart Rodrigo Duterte after the latter appeared to call him a "son of a whore".

Duterte also warned Obama to keep off the subject of extrajudicial killings in his country's brutal drug war, when they were due to meet on Tuesday at a regional summit in Laos, reports the Guardian.

Responding to question about how he intended to explain the extrajudicial killings to the US President, before boarding a plane to Laos for the Association of South-east Asian Nations summit (ASEAN), he said, "You must be respectful. Do not just throw away questions and statements. Son of a whore, I will curse you in that forum."

"We will be wallowing in the mud like pigs if you do that to me," he added.

Reports suggest that when the comments reached the Obama camp, he initially asked his staff to find out whether holding the meeting as scheduled would be useful.

"What I've instructed my team to do is to talk to their Philippine counterparts to find out, is if this in fact a time where we can have some constructive, productive conversations," Obama said at the end of a G20 Summit in the eastern Chinese city of Hangzhou.

Asserting that Filipino people are some of our closest friends and allies and the Philippines is a treaty ally of ours, he said, "I always want to make sure that if I'm having a meeting that it's actually productive and we're getting something done."

However, hours later a White House spokesman said that a decision has been made to cancel the meeting.

Obama will instead meet South Korean President Park Geun-hye.

The Philippine President has faced condemnation from human rights campaigners, diplomats and the UN for inciting a war on drugs.

According to official figures released on Sunday, at least 2,400 deaths have taken place in just two months.

Duterte in the past had has responded to critics with a string of outbursts.

He labelled the US ambassador to Manila a "gay son of a whore", telling the Catholic church "don't fuck with me", and has accused the UN of issuing "shitting" statements about his anti-drugs policies.