Former New Jersey Gov. Chris Christie, a staunch ally of Donald Trump, called the president's legal team a "national embarrassment" on Sunday as the president's campaign has mounted failed legal challenges to the 2020 election.

Christie appeared as a panelist on “This Week With George Stephanopoulos," and offered a sharp rebuke to Trump's legal strategy and said Trump should concede the election to Joe Biden.

Christie, who in December 2018 bowed out of consideration to serve as White House chief of staff, called out Trump's attorney Sidney Powell.

"The president has had an opportunity to access the courts ... if you have got the evidence of fraud, present it," Christie said.

"What has happened here, quite frankly, the conduct of the president's legal team has been a national embarrassment.

"Powell accusing [Georgia] Gov. Brian Kemp of a crime on television yet being on unwilling to go on TV and defend and lay out the evidence that she supposedly has -- this is outrageous conduct by any lawyer. Notice that they won't do it inside the courtroom. They allege fraud courtroom outside the courtroom but when they go inside the courtroom they don't plead fraud and they don't argue fraud,” Christie said.

“Listen, I’ve been a supporter of the president's. I voted for him twice. But elections have consequences and we cannot continue to act as if something happened here that didn’t happen.”

Christie, who previously served as a federal prosecutor, suggested that Trump's legal team may not have evidence of voter fraud.

"You have an obligation to present the evidence. The evidence has not been presented," he said.

"The country is what has to matter the most. As much as I'm a strong Republican, and I love my party, it's the country that has to come first."

Some Twitter users took exception to Christie's comments.

There were others who agreed with Christie's comments.

Christie served as governor of New Jersey from January 2010 to January 2018. In 2016, he ran for president but failed to gain much traction in the Republican primaries.

Chris Christie
Former New Jersey Gov. Chris Christie fields questions at a wide-ranging news conference at the Statehouse in Trenton, New Jersey, March 3, 2016. Getty Images/ Jeff Zelevansky