AKIPRESS.COM - U.S. President Barack Obama cancelled his first meeting with Philippines counterpart Rodrigo Duterte on Tuesday after the blunt-spoken Duterte described him as a "son of a bitch", casting a shadow over a gathering of Asian leaders in Laos, Reuters reports.

Duterte, who has been roundly criticised abroad for a 'war on drugs' that has killed about 2,400 people since he took office two months ago, said hours later that he regretted his comments "came across as a personal attack" on the U.S. president.

"President Duterte explained that the press reports that President Obama would 'lecture' him on extrajudicial killings led to his strong comments, which in turn elicited concern," the Philippines government said.

"He regrets that his remarks to the press have caused much controversy," it added in a statement released at the summit in Vientiane, the capital of Laos.

The White House had earlier said Obama would not pull any punches on his concerns about human rights abuses in the Philippines, its treaty ally, when meeting Duterte.

Duterte responded to that with his "son of a bitch" comment to reporters on Monday before leaving to join fellow leaders of Southeast Asian and East Asian leaders for the summit.

Obama learned about the insult as he emerged from the Group of 20 summit in Hangzhou, China. At a news conference, he said he had told his aides to speak with Philippine officials "to find out is this, in fact, a time where we can have some constructive, productive conversations."

Hours later, his aides said the meeting had been cancelled.

Instead, Obama plans to meet South Korean President Park Geun-hye on Tuesday, said Ned Price, spokesman for the White House National Security Council - a meeting where the response to North Korea's latest missile tests is expected to be on the agenda.