The Philippines' new leader, Rodrigo Duterte, expressed regret Tuesday for comments in which he called U.S. President Barack Obama a "son of a bitch" as the two leaders sought to tamp down controversy over an incident that could also affect Japan.

In the announcement, which came ahead of a bilateral meeting with Prime Minister Shinzo Abe on the sidelines of a key leaders' summit, Duterte said the talks with Obama had been rescheduled after Washington pulled out of them earlier in the day.

"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 U.S. president," a statement released by Duterte said.