Philippines President Rodrigo Duterte is expressing regret after his obscenity-laden rant against President Barack Obama prompted the White House to cancel planned bilateral talks between the two leaders, reports CNN.

Duterte, who cursed Obama as a "son of a bitch" Monday, said in a statement through his spokesman that he regretted "it came across as a personal attack on the US President."

White House officials previously said Obama would confront Duterte about his country's handling of drug dealers, including extrajudicial killings, which are government executions without the benefit of judicial proceedings.

"Who does he think he is? I am no American puppet. I am the president of a sovereign country and I am not answerable to anyone except the Filipino people," Duterte scoffed in a speech Monday. "Son of a bitch, I will swear at you."

Obama has worked hard to develop the Philippines' partnership with the US and as a regional counterbalance to China. He's visited the country twice in his second term, and announced on a stop there in November the return of a US military presence at a critical naval base on the South China Sea.

But Duterte's derogatory comments and a spike in extrajudicial killings of suspected drug dealers put the relationship in stormier waters.

Obama and Duterte had been set to meet in Laos this week, where Obama is attending a meeting of Southeast Asian leaders. The statement from Duterte's spokesman said the "meeting has been mutually agreed upon to be moved to a later date."

Obama instead will meet on Tuesday with President Park Geun-hye of South Korea.

In his speech Monday, Duterte also blamed the United States for causing the unrest on the southern Philippines island of Mindanao.

"As a matter of fact, we inherited this problem from the United States," he said. "Why? Because they invaded this country and made us their subjugated people. Everybody has a terrible record of extrajudicial killing. Why make an issue about fighting crime?"

He added: "Look at the human rights of America along that line. The way they treat the migrants there."

Obama indicated Monday he was wary of meeting with Duterte, suggesting the bombast could prevent making substantial progress between the two nations.

"I always want to make sure if I'm having a meeting that it's productive and we're getting something done," Obama said during a news conference.

"If and when we have a meeting, this is something that is going to be brought up," Obama said, referring to the Philippines' controversial record of combating drug crime since Duterte took office earlier this year.