President Donald Trump pushed back today against reports of a growing rift between himself and his chief of staff, declaring that John Kelly is "doing a fantastic job" and dismissing rumblings that the ex-Marine may soon leave the White House. Just days after it was reported that Kelly had called Trump "an idiot" to staffers, Trump showcased his support for his embattled chief of staff by walking with him to a group of reporters at Joint Base Andrews awaiting Air Force One's departure for Dallas. The president, who was set to speak at the National Rifle Association convention, blasted the stories as "false reporting" while Kelly said everything at the White House was going "phenomenally well." That stands in stark contrast to what Kelly has said privately in recent weeks. He has cast himself as safeguarding the public from the president and has threatened to quit the White House on several occasions. Kelly's "idiot" remark, confirmed to The Associated Press by a former administration official not authorised to publicly discuss private conversations, came as his clashes with Trump over policy and personnel grew louder and more frequent. The remark was first reported Monday by NBC News. In a statement Monday, Kelly called the report "total BS," and characterised his relationship with Trump as "incredibly candid and strong." He added of the president, "He always knows where I stand and he and I both know this story is total BS." In recent months, Trump has chafed at Kelly's management style and has occasionally talked with friends about replacing him. Indeed, Trump has floated the idea of appointing Kelly to run the Department of Veterans Affairs in calls with outside allies, said two people familiar with the conversations, though there are other possibilities in the mix and the president often floats ideas without taking action. Kelly has made clear he wouldn't accept such an offer. In his early days in the White House, Kelly imposed strict controls on access and the flow of information to Trump, though his direct influence has waned somewhat since then, aides said. Kelly allies insist he has merely trained the staff to follow his management protocols, but officials note that Trump has grown more willing to act unilaterally, ignoring or simply not seeking out the advice of his top aide. The disagreements between the retired four-star general and the businessman-turned-president have grown more animated, and on one such occasion last year Kelly blasted the president as "an idiot" to staffers, the former administration official told the AP. Kelly has also told confidants that he has at times served as a guardrail, protecting the American people from Trump, according to a person familiar with his views. The person, and others who spoke about private conversations, was not authorised to discuss private conversations by name and requested anonymity. Frustrated with his chief of staff, Trump has taken to paying more attention to the advice of former campaign aides like Corey Lewandowski, who appeared alongside the president at a rally in Michigan Saturday. During the rally, which one person likened to a trial, Trump called Lewandowski on stage and praised him for not being a "pushover" or a "patsy." The president also recently told an ally that he was still frustrated by an interview that Kelly gave to Fox News more than three months ago in which he suggested that Trump had "evolved" in his thinking about the need for a wall on the Mexican border. Trump's anger about that remark \u2014 the president believed it insulted his intelligence and made him look like a flip-flopper on a signature campaign issue \u2014 was "the beginning of the end" for Kelly, according to several Trump confidants. Kelly's handling of domestic violence accusations against then-White House staff secretary Rob Porter earlier this year also caused consternation among White House staffers, who believed Kelly wasn't truthful. Kelly has told people close to him that while he wanted to make the one-year mark in the position \u2014 that would mean late July \u2014 though he no longer is confident he will.