Lt. Gen. H. R. McMaster, the battle-tested Army officer tapped as President Trump’s national security adviser last year to stabilize a turbulent foreign policy operation, will resign and be replaced by John R. Bolton, a hard-line former United States ambassador to the United Nations, White House officials said Thursday.

General McMaster will retire from the military, the officials said. He has been discussing his departure with President Trump for several weeks, they said, but decided to speed up his departure, in part because questions about his status were casting a shadow over his conversations with foreign officials.

The officials also said that Mr. Trump wanted to fill out his national security team before his meeting with North Korea’s leader, Kim Jong-un. He replaced Secretary of State Rex W. Tillerson with the C.I.A. director, Mike Pompeo, last week.