MSNBC host Lawrence O’Donnell said Wednesday he made an "error in judgment" and should not have reported information about the president’s finances from a single source on air Tuesday night and formally retracted the statement Wednesday night.

On Tuesday, O'Donnell reported that President Donald Trump's financial records show that some of his loans have Russian co-signers.

"The Last Word" host opened his show Wednesday night by saying he repeated statements from a single source that weren't ready for reporting and that he did not go through the network's "rigorous verification and standards process" before repeating it, and that "had it gone through that process, I would not have been permitted to report it."

"Tonight, we are retracting the story," O'Donnell said. "We don't know whether the information is inaccurate, but the fact is we do know it wasn't ready for broadcast, and for that I apologize."

O’Donnell tweeted earlier Wednesday that his reporting Tuesday night, which cited a single unnamed source close to Deutsche Bank, did not meet "our rigorous verification and standards process."

"Last night I made an error in judgment by reporting an item about the president's finances that didn’t go through our rigorous verification and standards process. I shouldn't have reported it and I was wrong to discuss it on the air," O’Donnell said.

Last night I made an error in judgment by reporting an item about the president’s finances that didn’t go through our rigorous verification and standards process. I shouldn’t have reported it and I was wrong to discuss it on the air. I will address the issue on my show tonight. — Lawrence O'Donnell (@Lawrence) August 28, 2019

O’Donnell reported Tuesday that the unnamed source close to Deutsche Bank revealed to him that loans taken out by Trump were co-signed by "Russian billionaires."

NBC News has not viewed the Deutsche Bank records and has not been able to verify what the source told O'Donnell.

Later in the show, O’Donnell returned to the subject and said the claim was "going to need a lot more verification before it’s a provable fact."

Responding to O’Donnell's reporting, an attorney for Trump sent a letter on Wednesday to NBC News calling the segment "false and defamatory" and demanding the host "immediately and prominently retract, correct and apologize" for the statements.

The attorney, Charles Harder, added that "the only borrowers under these loans are Trump entities, and Mr. Trump is the only guarantor."

O’Donnell's reporting referred to tax returns and financial records tied to Trump that Deutsche Bank said Tuesday it possessed. The bank's statement was the latest development related to an effort by House Democrats to obtain the president's financial information.

A spokesperson for MSNBC referred questions to O'Donnell's tweet and declined to comment on the on-air retraction.

O'Donnell on Wednesday night's show referred to the demand for a retraction by the president's attorneys.

"Saying 'if true' as I discussed the information was simply not good enough," O'Donnell said. "I should not have said it on air or posted it on Twitter. I was wrong to do so."