The agency ceased protecting Mr. Trump, who lives in New York City and is an executive at the Trump Organization, last week. Mr. Trump, an avid camper and hunter, was said to be seeking more privacy than he can expect with a contingent of agents accompanying him everywhere.

It was not immediately clear whether the decision applied to his family; he and his wife, Vanessa, have five children. Mr. Trump could not be reached, and the White House did not return a message seeking comment.

Additionally, Kellyanne Conway, a counselor to President Trump, will no longer be covered by agents, according to an administration official briefed on the matter.