US President Donald Trump directed his acting chief of staff, Mick Mulvaney, to leave the room to cough when his top aide let out a short rasp during the President's back-and-forth in the Oval Office with George Stephanopoulos of ABC News.

"If you're going to cough, please leave the room," Trump said during one segment of the lengthy interview, which aired yesterday.

He shook his head as he warned Mulvaney, "You just can't, you just can't cough."

The President was in the middle of answering a question about his financial records when he became distracted by the sharp sound of his chief of staff expelling air from his lungs.

Trump tripped over his words, requesting to Stephanopoulos, "Let's do that over." Appearing to point at Mulvaney, he said, "He's coughing in the middle of my answer."

As an aside to Stephanopoulos, Trump said: "I don't like that, you know. I don't like that." The ABC anchor and chief political correspondent laughed, remarking, "Your chief of staff."

The President asked if the ABC team wanted to do the shot over, and then went back to discussing his financial statements, maintaining that he would like to make them available to the public. Pressed by Stephanopoulos, who noted, "It's up to you," Trump claimed: "No, it's not up to me. It's up to lawyers; it's up to everything else."

Just over 20 seconds into this clip Trump gruffly asks Mick Mulvaney to leave the room because he coughed. No, seriously. Watch it for yourself.

Well adjusted people with a shred of empathy simply don’t behave this way. pic.twitter.com/5aKfTVruRK

— Aaron Rupar (@atrupar) June 17, 2019

Trump has explained his decision to withhold his tax returns by asserting without evidence that they are under audit and claiming that the public isn't interested in them. His move had broken with the custom of every president since Jimmy Carter. It also appears to go against the findings of the IRS, which indicated in a memo last month that only the rare invocation of executive privilege can thwart a congressional subpoena for the tax information.

Last week, the Justice Department weighed in, unveiling its rationale for backing the decision of Treasury Secretary Steven Mnuchin to refuse to relinquish the documents to Congress. The 33-page memo from the law enforcement agency argued that House Democrats were intent on making the records public, which served no "legitimate legislative purpose" - the Administration's catchall answer to congressional requests.

The fight over Trump's financial records is just one front in the deepening battle between Congress and the White House over secrecy and oversight - a battle that has infected relations between the two branches.

But a more literal fear of contagion has long occupied the President, who has called himself a "germaphobe" and labelled the practice of shaking hands "barbaric." He reportedly abstains from pressing the ground-floor lift button because it sees such frequent finger traffic.

In a 1993 interview with Howard Stern, the radio personality known for his shock-jock style, Trump confessed to having "germ phobia."

In the conversation, broadcast on E!, Stern apologised to the real estate mogul for "spitting all over you." The self-proclaimed "King of all Media" presumed that the stray saliva was more than a slight indiscretion, asking, "I shouldn't spit all over you because you have germ phobia, true?"

Trump replied, "I do have germ phobia." He said he washed his hands "as many times as possible" each day, the businessman said, and allowed, "It could be a psychological problem."

But Trump said there was no need to see a psychiatrist for what Stern called "obsessive-compulsive" behaviour.

"No," he said. "I like it. I like cleanliness. Cleanliness is a nice thing. Not only hands: body, everything."

A fuller account of Trump's insistence on cleanliness came in his 1997 book, Trump: The Art of the Comeback, written with Kate Bohner.
"One of the curses of American society is the simple act of shaking hands, and the more successful and famous one becomes the worse this terrible custom seems to get," the book explains. "I happen to be a clean hands freak. I feel much better after I thoroughly wash my hands, which I do as much as possible."

Since his election, Trump has sought to leverage his aversion to germs to gain ground against his political adversaries. In a news conference in January 2017, he dismissed allegations - included in the dossier compiled by the former British intelligence agent Christopher Steele - that Russia had gathered compromising material on him during his stay in a Moscow hotel.

"Does anyone really believe that story?" said the President-elect, as a grin crept onto his face. "I'm also very much of a germaphobe, by the way."

Then he tacked on his signature, "Believe me."