US President Barack Obama and Philippine President Rodrigo Duterte exchanged pleasantries late yesterday before attending a gala dinner at the Asean summit, Philippine officials said.

The brief encounter came two days after Obama cancelled a meeting between them due to crude comments Duterte had directed at the US president.

Obama and Duterte shook hands and talked briefly before attending the dinner to conclude the second day of the leaders’ summit of the Association of South-East Asian Nations (Asean) in Vientiane, Laos.

“They met at the holding room. They were the last persons to leave the holding room,” Foreign Secretary Perfecto Yasay said, insisting that the countries’ relationship was “firm, very strong”.

A White House official said the exchange “consisted of pleasantries between the two”.

The two leaders were supposed to meet one-on-one on Tuesday, but Obama cancelled the meeting after Duterte warned him and other leaders against questioning his bloody anti-drug campaign with the words “son of a bitch”.

Philippine Senator Alan Peter Cayetano said the “warm handshake and good conversation” between Obama and Duterte was a sign that “all’s well that ends well”, adding, “There was an efforts on both sides to patch things up.”

Marciano Paynor, chief Philippine protocol officer and incoming Philippine ambassador to the United States, said Duterte was learning “quick” during the summit, his international debut since becoming president on June 30.

“We have to give him time because he’s used to (being) a local executive - you do what you want, you say what you want,” he said. “You cannot distinguish what is proper, what is not.”

Duterte has expressed “regret” that his expletive-laden remarks “came across as a personal attack on the US president”.

“Son of a bitch, I will swear at you at that forum,” he said on Monday, when asked how he would respond to questions about the spate of killings amid his government's anti-drug campaign. “You must be respectful.”

“Clearly he’s a colourful guy,” Obama told reporters in Hangzhou, China, after learning of the remarks.

“We recognise the significant burden that the drug trade plays not just in the Philippines, but around the world and fighting narco-trafficking is tough,” he said. “But we will always assert the need to have due process and to have that fight against drugs in a way that is consistent with international norms.”

According to police statistics, 1,011 suspected drug users and dealers have been killed in police operations between July 1 and Sept 4. Police also recorded 1,391 deaths during the same period which are still being investigated.

Duterte has stressed he did not want to pick a fight with Obama, but added, “Nobody but nobody should interfere. This is an independent country. Nobody has the right to lecture me... If you do that, we will end up insulting each other.”

- dpa