Mr. Obama, who arrived inLaoslate Monday night to become the first U.S. president ever to visit the Southeast Asian country, is encountering more than his usual share of friction and confrontation on his 10th trip to the region.

It started with his arrival at the airport in China, where Chinese officials failed to provide a portable staircase for Mr. Obama to disembark from the upper door of Air Force One with the typical grandiose visibility befitting a visiting head of state. Instead, the president emerged from a smaller staircase in the belly of the aircraft, and many saw it as a deliberate sign of disrespect by the Chinese.

Republican nominee Donald Trump said he would have refused to meet with Chinese officials if they treated him like they treated Mr. Obama.

"If that were me, I’d say, ‘You know what, folks, I respect you a lot, let’s close the doors, let’s get out of here,’ ” he said Monday.

Mr. Obama downplayed the episode, and Chinese officials blamed the U.S. for not requesting a staircase.