White House press secretary Sean Spicer at a briefing. REUTERS/Kevin Lamarque ABC reporter Jonathan Karl pressed White House press secretary Sean Spicer on Monday over Spicer's inaccurate claims about the size of inaugural crowds.

During what President Donald Trump's team dubbed the "first official press briefing," Karl confronted Spicer about his Saturday statement that Trump's inauguration was the "largest audience to ever witness an inauguration — period — both in person and around the globe," despite evidence to the contrary.

"Is it always your intention to tell the truth on that podium, and do you pledge to never to knowingly say something that is not factual?" Karl asked.

Spicer said that his intention was "never to lie" to reporters and that the administration and journalists could "disagree on the facts."

"There are times we believe something to be true or we get something from an agency or we act in haste because the information available wasn't complete, but our desire is to communicate with the American people and make sure you have the most complete story at the time, so we do it," Spicer said.

"I'm going to come out here and tell you the facts as I know them, and if I make a mistake, I'll do my best to correct it," he added.

The size of the crowd at Friday's inauguration became a source of debate after Trump said on Saturday that more than 1 million people attended.

There are no official government estimates of the crowd size, but independent estimates put it at closer to 250,000 attendees, while metro ridership statistics and photographs comparing Trump's inauguration with past inaugurations suggested that the number was far lower than the White House claimed.

Spicer also attempted to point out the media's errors, noting Time reporter Zeke Miller's inaccurate Friday report that the Marin Luther King Jr. bust in the Oval Office was removed — a brief report that Miller quickly corrected and apologized for.

"You're in the same boat. There are times when you tweet something out or you write a story and you publish a correction. That doesn't mean that you were intentionally trying to deceive the American people, does it?" Spicer said. "And I think that we should be afforded the same opportunity."

Spicer said that the information he was provided on Saturday, which was given to him by the inaugural committee, "came from an outside agency," and he highlighted the millions of people who watched on TV and streaming services.

The press secretary said that he never claimed that the inauguration had the largest in-person audience, saying he always meant the total audience of viewers for the inauguration.

"I didn't say in person — both in person and around the globe to witness it," Spicer said. "I don't know how I could interpret that differently. That's literally what I said, to witness it both in person and around the globe."

Later in the press conference, Spicer said that it was "not about the crowd size," citing commentary and punditry suggesting that Trump could not win key states in the 2016 election.

"There is this constant theme to undercut the enormous support that he has," Spicer said. "And I think it is unbelievable frustrating when you're told it's not big enough, it's not good enough, you can't win."

Spicer's comments on Saturday raised concern from several former White House officials.

Jay Carney, President Barack Obama's second press secretary, voiced his displeasure with Spicer's insistence on the crowd size on Twitter.

During an appearance on CBS on Monday, Ari Fleischer, a press secretary for President George W. Bush, urged Spicer to correct his error.

"It concerns me. It's one thing to take on the press — that's a time-honored tradition in Washington, DC," Fleisher said. "The part about how people showed up in the audience at the inauguration, who cares. It's not worth fighting over."