“While the immediate cause was my strong comments to certain press questions that elicited concern and distress we also regret it came across as a personal attack on the US president,” a statement released by Duterte said.

The 71-year-old former prosecutor was referring to his remarks on Monday, when he warned he would not be lectured by Obama over concerns about a brutal war on drug crime that has claimed more than 2,400 lives in the Philippines.

“You must be respectful. Do not just throw away questions and statements. Son of a whore, I will curse you in that forum,” Duterte told reporters when asked about his message for Obama.

Duterte, who has quickly earned a global reputation for his jibes, then used typically colourful language to describe their planned meeting if rights issues came up.

“We will be wallowing in the mud like pigs if you do that to me,” he said.

Duterte likely had realised his folly by the time he arrived in the Laotian capital of Vientiane on Monday night.

Speaking to reporters here, he said: “I do not want to quarrel with the most powerful country on the planet,” but immediately took his typical combative approach by saying: “Washington has been so liberal about criticising human rights, human rights and human rights. How about you? I have so many questions also about human rights to ask you. So ... people who live in glass houses should not” throw stones at others.

He said if the White House had problems with him, it could have sent him a diplomatic note and let him respond. “There’s a protocol for that,” Duterte said. “You just cannot shoot a statement against the president of any country.”

But by Tuesday, he had done a complete U-turn in the tone of his statement, saying both sides would hold face-to-face talks “at a later date”.

“Our primary intention is to chart an independent foreign policy while promoting closer ties with all nations especially the US with which we have a longstanding partnership,” Duterte’s statement said.

The Philippines’ Department of Foreign Affairs added Duterte had “a deep regard and affinity for President Obama and for the enduring partnership between our nations”.

Duterte has angrily rejected criticism from the Catholic Church, human rights groups, legislators and the United Nations over his drug purge.

During his Monday outburst he said the bloodbath would continue.

“More people will be killed, plenty will be killed until the last pusher is out of the streets. Until the (last) drug manufacturer is killed, we will continue and I will continue,” he said.

He also added he would not take orders from the United States, a former colonial ruler of the Philippines, and did not care about how he was perceived.

“I don’t give a sh** about anybody observing my behaviour,” he said.

Additional reporting by Associated Press