President Donald J. Trump announced Wednesday that Keith Schilling, who served as the president’s chief strategist, had died of a heart attack.
Schiller, who also served as senior counselor to the president and chief of the office of policy planning, was 58.
Trump said he had spoken with Schiller by phone and was heartbroken.
“He was a wonderful human being, and I have lost a great friend, and he will be missed very greatly,” Trump said in a statement.
Schilling was a longtime adviser to the Trump White House and was known for his combative style of speaking.
His comments about the media and political establishment often caused friction with his boss, who has been criticized for his own use of social media.
Trump also named Vice President Mike Pence as acting chief of protocol and deputy national security adviser for foreign affairs and national security.
Pence will also serve as the acting director of the Office of Public Engagement and the Office for Public Engaging Government, a transition official said.