Donald Trump has accused the media of lying about the turnout at his inauguration ceremony - and warned reporters are going to pay a "big price" for their alleged dishonesty.
The President insisted that crowds at the event stretched back all the way to the Washington Monument, even though photographs and footage from the scene showed large, empty spaces around the landmark.
Press Secretary Sean Spicer went one further during a heated White House briefing on Saturday night, describing it as "the largest audience ever to witness an inauguration, period".
He also claimed that white "floor coverings" used to protect the grass during the ceremony had unfairly drawn attention to empty spaces on the National Mall.
With pictures from Mr Trump's inauguration on TV screens beside him, Mr Spicer added: "Attempts to lessen the enthusiasm of the inauguration are shameful and wrong."
Although the National Park Service no longer provides estimates of crowds at inaugurations, photographic evidence shows substantially more people turned out for Barack Obama's ceremony in 2009.
Mr Spicer also criticised a reporter who wrongly stated that President Trump has removed a bust of Martin Luther King Jr from the Oval Office.
"There's been a lot of talk in the media about the responsibility to hold Donald Trump accountable, and I'm here to tell you it goes two ways. We're going to hold the press accountable as well," the White House official warned.
During the briefing, the Press Secretary did not take questions from the press.
The latest spat between the new administration and the media came as Mr Trump attempted to repair relations with the US intelligence community during a visit to CIA headquarters.
The new President has spent weeks criticising America's security agencies over their claims that Russia attempted to skew the results of the election.
He went as far as claiming that outgoing CIA director John Brennan was a "leaker of fake news".
But, on his first full day in office, Mr Trump visited the CIA's base at Langley in Virginia and told employees the
media had invented a "feud".
He said he was behind them 1,000%, adding: "There is nobody that feels stronger about the intelligence community and the CIA than Donald Trump.
"I'm so behind you. You're going to get so much backing that you're going to start saying, 'Don't give us so much backing.'
"I love you, I respect you, there is no one I love more, we are going to start winning again and you will be leading the charge."
He also vowed: "We have to get rid of ISIS. Radical Islamic terrorism needs to get eradicated off the face of the earth."
The President riffed on his election success, how young he feels, how popular he remains with the men and women of the US military, and hinted at a third Iraq war.
Mr Trump had risked alienating the intelligence community that now reports to him with his reaction to their investigation into hacking of Democrats during the presidential election campaign.
Director of National Intelligence James Clapper told a congressional committee that such "disparagement" risked undermining the relationship.
Earlier on Saturday, Mr Trump attended an inaugural interfaith prayer service at Washington's National Cathedral. He was joined by First Lady Melania and much of the extended First Family.
On his ride back to the White House, the presidential motorcade crossed paths with a number of protesters making their way to the huge march on Washington.
Hundreds of thousands of people descended on cities across the US to protest against Mr Trump's presidency.
Since taking office, the 45th President has begun putting some of his campaign promises into action, including a move to begin dismantling Obamacare.
His new defence secretary, retired Marine General James Mattis, paid a visit to the Pentagon hours after he was confirmed and sworn in.
Mr Trump also confirmed Theresa May would visit the White House next week - either on Thursday or Friday.
It appears likely the Prime Minister will be the first foreign leader to meet the new President since his inauguration.