Chief of staff John Kelly: 'I'm not quitting today ... I don't think I'm being fired today' President Trump previously tweeted that rumors Kelly would be fired were false.

 -- White House chief of staff John Kelly forcefully pushed back on rumors of discord between him and President Donald Trump on Thursday, telling reporters that he has no plans to resign or reason to believe he will be fired.

"Although I read it all the time, pretty consistently, I'm not quitting today," Kelly said in his first public appearance at a White House press briefing. "I don't believe -- and 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."

On Tuesday, Trump tweeted praise for Kelly, writing that "The Chief is doing a FANTASTIC job" and disputing reports that he would be fired. The president did not identify the source of the referenced reports, though stories from multiple news organizations earlier in the week described the relationship between Trump and Kelly as on tenuous footing.

Kelly, a retired four-star Marine general, took office as chief of staff in late July after the resignation of Reince Priebus. He previously served just over six months as Secretary of Homeland Security. On Tuesday, after expressing the optimism about his job security, he characterized his role as a difficult, but critical one.

"I will tell you, this is the hardest job I've ever had," said Kelly. "This is, in my view, the most important job I've ever had."

When asked by one reporter about how he phrased his "not so frustrated" comment and if he felt foiled in any way, the chief of staff continued with a response similar to his prior remarks.

"No, I'm not frustrated," he said. "This is really, really hard work -- running the United States of America. I don't run it, but I'm working for someone who is dedicated to serving the country in the way he talked about for a number of years."

"My only frustration, with all due respect to everyone in the room, is when I come to work in the morning and read about things I allegedly said, or things that Mr. Trump allegedly said, or people who are going to be fired or whatever and It's just not true," Kelly continued. "That's my frustration; I mean no disrespect to you all."

Kelly went on to share his opinion on the medium used by Trump to defend the chief of staff on Tuesday: Twitter. He was asked whether Trump's social media habit makes his job harder.

"No. No," Kelly said. "The job of the chief of staff is to staff the president, give him the best advice or go get the best advice I can give him, help him consume advice, help him work through the decision-making process in an informed way. But that's my job and that's what I do."