Yet if Mr. Kelly’s rare moment in the news media spotlight was partly about presidential cleanup, it also was perfectly clear that he knew Mr. Trump would be watching.
With the cameras rolling, Mr. Kelly put in an enthusiastic plug for a border wall, lectured reporters about getting “better sources” and insisted that he had no intention of trying to control the president’s tweeting. He called Mr. Trump “a man of action” and “a straightforward guy.”
Such is the tightrope that a chief of staff in a Trump presidency must walk: simultaneously demonstrating a sense of calm and order inside the White House while being careful not to appear critical of the president’s lack of those very qualities.
“His goal seemed to be to reassure people that there’s a grown-up in the room with Trump,” said Chris Whipple, the author of “The Gatekeepers,” a book about White House chiefs of staff. “In the midst of all the chaos and the back-stabbing in the West Wing, he looks like a grown-up. He smiles. He seems reasonable. All of that is a plus.”
If there was any doubt that Mr. Kelly faces a difficult balancing act, the chief’s first task on Thursday was to beat back rumors that his own job is in immediate jeopardy. In doing so, he became the second top Trump official in a week to insist he is not about to be fired.
“I would just offer to you that although I read it all the time pretty consistently, I’m not quitting today,” Mr. Kelly quipped, referring to news reports that have suggested he is discouraged at the White House and on the outs with Mr. Trump. “I just talked to the president — I don’t think I’m being fired today. And I’m not so frustrated in this job that I’m thinking of leaving.”
Last week, Secretary of State Rex W. Tillerson faced a similar task after reports that he had called Mr. Trump a “moron.” But where Mr. Tillerson was awkward and brusque during a similar face-off with the press, Mr. Kelly was smooth and genial.
His only frustration, Mr. Kelly said, was repeatedly reading untrue stories about things Mr. Trump said, or of people who are about to be fired.
“That’s my frustration,” he said, “and I mean no disrespect to you all.”
Mr. Kelly also sought to avoid adding to the week’s clash between Mr. Trump and Senator Bob Corker, Republican of Tennessee. Asked about Mr. Corker’s harsh comments about the president, Mr. Kelly carefully gave a nod to Mr. Trump’s anger.
“There’s others that are, as the president will say, grandstanding,” the chief of staff said. “I’m not saying Senator Corker is that way; I’m just saying that some people grandstand and kind of enjoy the attention.”
When Mr. Kelly became chief of staff in July, he moved quickly to try to contain the turmoil of the president’s first six months with a new discipline inside the West Wing. Meetings became crisper, and walk-in access to the Oval Office was sharply curtailed.
Mr. Kelly acknowledged the value of those changes on Thursday, saying that “when we go in to see him now, rather than onesies and twosies, we go in and help him collectively understand what he needs to understand to makes these vital decisions.”
But he denied that his job is to control the president, and he chuckled about the idea that he wields an “iron hand” inside the West Wing.
“Just put some organization to it. Put a smile on my face,” Mr. Kelly said, lamenting that “you guys with the cameras always catch me when I’m thinking hard and it looks like I’m frustrated and mad.”
Mr. Kelly insisted that was not the case, though he said that being Mr. Trump’s chief of staff was not the best job he had had. (That title is reserved for the time he served as an enlisted Marine sergeant infantryman, he said.)
As if to underscore the point, when a member of the press corps started his question by offering “congratulations” to Mr. Kelly, he prompted laughter with a wry quip:
“For what?” he said.