White House chief of staff John Kelly has reportedly denigrated President Donald Trump in private on multiple occasions, NBC News reported Monday.

Kelly, who reportedly casts himself as a savior of the administration, has reportedly called Trump an "idiot."

"He says stuff you can't believe," a senior White House official told NBC.

Kelly dismissed the claims as "total BS" in a statement on Monday.

White House chief of staff John Kelly has reportedly denigrated President Donald Trump in private on multiple occasions, questioning the president's intelligence and casting himself as the country's savior, according to a Monday NBC News report.

Kelly has referred to Trump as an "idiot" multiple times, four officials who say they've witnessed the remarks told NBC. And the former department of homeland security chief is particularly critical of what he reportedly sees as Trump's weak understanding of policy, particularly immigration-related.

"He doesn't even understand what DACA is. He's an idiot," Kelly said in a meeting about the program that protects hundreds of thousands of undocumented immigrants brought into the country as children, according to two officials in attendance. "We've got to save him from himself."

Kelly has made public comments about what he called Trump's evolution on immigration issues, telling Fox News in January that the president was not "fully informed" about the border wall and other policy proposals during his presidential bid.

"He says stuff you can't believe," a senior White House official told NBC of Kelly. "He'll say it and you think, 'That is not what you should be saying.'"

Kelly denied the claims on Monday, calling them a "pathetic attempt to smear" him.

"I spend more time with the president than anyone else and we have an incredibly candid and strong relationship. He always knows where I stand and he and I both know this story is total BS," Kelly said in a statement. "I am committed to the president, his agenda, and our country."

He went on, "This is another pathetic attempt to smear people close to President Trump and distract from the administration's many successes."

In perhaps the most controversial moment of his tenure as chief of staff, Kelly was heavily criticized for his role in a scandal surrounding former White House staff secretary Rob Porter, who resigned from his post after his two former wives publicly accused him of physical and verbal abuse.

Kelly, who reportedly knew of issues with Porter's security clearance for months, released a statement praising the top staffer as "a man of true integrity and honor," even after the abuse allegations were published in the media. In another statement more than 24 hours later, Kelly said he was "shocked by the new allegations," but continued to defend Porter, who called the claims "a coordinated smear campaign."

The president, who lavished praise on Porter after the staffer's resignation, was reportedly privately furious with Kelly's response to the situation. Kelly later said he mishandled his response to the allegations.

Current and former White House officials told NBC that Kelly wondered aloud how much more Porter would have to go through before his reputation could be restored.

Kelly has also reportedly made occasional remarks that disturbed female staffers, including asserting that women are more emotional than men — a claim he made in front of the president, four sources said.

And Trump has reportedly grown frustrated with Kelly over the last several months, sidelining him in important personnel and policy discussions and increasingly making decisions without his input.

Current and former White House officials told NBC they don't think Kelly will last past July — his one-year mark in the White House.