"Although I read it all the time, pretty consistently ... I'm not quitting today. I don't believe, and I just talked to the president, I don't think I'm being fired today," Kelly quipped during a surprise appearance in the White House briefing room.
"I'm not so frustrated in this job that I'm thinking of leaving," he said, adding the job was the hardest and most important job he had ever had.
Mr Kelly also said on Thursday his role was not to control President Donald Trump or his Twitter habit.
"I was not brought to this job to control anything but the flow of information to our president so that he can make the best decisions," Kelly told reporters.
"I was not sent in to or brought in to control him and you should not measure my effectiveness as a chief of staff by what you think I should be doing," he said.
