WASHINGTON — When President Trump called President Rodrigo Duterte of the Philippines on Saturday, White House officials saw it as part of a routine diplomatic outreach to Southeast Asian leaders. Mr. Trump, characteristically, had his own ideas.

During their “very friendly conversation,” the administration said in a late-night statement, Mr. Trump invited Mr. Duterte, an authoritarian leader accused of ordering extrajudicial killings of drug suspects in the Philippines, to visit him at the White House.

Now, the administration is bracing for an avalanche of criticism from human rights groups. Two senior officials said they expected the State Department and the National Security Council, both of which were caught off guard by the invitation, to raise objections internally.

The White House disclosed the news on a day when Mr. Trump fired up his supporters at a campaign-style rally in Harrisburg, Pa. The timing of the announcement — after a speech that was a grievance-filled jeremiad — encapsulated this president after 100 days in office: still ready to say and do things that leave people, even on his staff, slack-jawed.