Obama cancels meeting with Philippine´s Duterte after offensive comment

US president Barack Obama has backed out of a planned meeting with Rodrigo Duterte, president of the Philippines, after the recently-elected leader referred to him as a "son of a whore".

The pair were scheduled to meet in Laos at a summit for the Association of Southeast Asian Nations after Obama flew from the G20 meeting in China.

Obama had raised concerns over extra-judicial killings of drug dealers in the Asian country, something that Duterte had called for during his short time as president.

During a press conference Duterte 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."

Initially Obama did not cancel the meeting, saying that he would instruct his staff to find out whether the planned meeting would be in any way useful.

"Obviously the Filipino people are some of our closest friends and allies and the Philippines is a treaty ally of ours," Obama said at a news conference in Hangzhou, China, where the G20 summit was being held. "But I always want to make sure that if I’m having a meeting that it’s actually productive and we’re getting something done."

But hours later Obama's aides called off the meeting.

Duterte has since apologised for the comments, saying that the immediate reply was a response to pressure from reporters, but his office has said that "we regret that it came across as a personal attack on the US president."

The Phillipine president has not been short of controversy since he took office in June, promising to oversee the deaths of 100,000 drug dealers, as well as insulting the mothers of Pope Francis and the US ambassador to Manila.