MSNBC’s Lawrence O’Donnell said Wednesday he made an “error in judgment” in reporting about supposed Russian ties to President Donald Trump’s finances without verifying the story.

O’Donnell’s admission came in a tweet Wednesday after a lawyer for Trump said the story was false and defamatory, and called on NBC News to apologize and retract it.

MSNBC had no comment on any potential disciplinary action for O’Donnell, saying he would address the matter on Wednesday’s show.

O’Donnell said in his tweet that the story, which led Tuesday night’s broadcast, “didn’t go through our vigorous verification and standards process. I shouldn’t have reported it and I was wrong to discuss it on the air.”

He said on the show that he’d been told that Deutsche Bank had documents showing that Russian oligarchs had co-signed loans for Trump. He said the report came from a single source, who he didn’t identify. The documents also supposedly reveal that Trump paid little in taxes, he 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

Even as O’Donnell talked about his story, he couched it several times, saying “if true.”

“That would explain, it seems to me, every kind word that Donald Trump has ever said about Russia and Vladimir Putin, if true, and I stress the ‘if true’ part of this,” he said on the air.

It exhibits a stunning lack of rigor for a news organization that was pounced upon by Trump’s lawyers. In a letter to Susan Weiner, NBC Universal’s general counsel, and Daniel Kummer, the company’s senior vice president for litigation, Trump lawyer Charles Harder called O’Donnell’s statements “false and defamatory, and extremely damaging.”

Harder said Trump is the only guarantor for the loans. He said it was information that was publicly recorded and could be found by an online search.

The president’s attorney threatened legal action if NBC did not apologize and correct the report.

O’Donnell also tweeted his story on Tuesday, and discussed it on the air with Rachel Maddow, MSNBC’s most popular personality, who hosts the show before his. She said in response “that is a scenario that I never contemplated.”

The episode is a blow to MSNBC, which has built powerful ratings with a prime-time lineup of liberal commentators Chris Hayes, Maddow and O’Donnell and is a comfortable home to Trump opponents. Many nights, it is the second most-watched cable network, behind only Fox News Channel, whose lineup of conservative hosts appeals to the president’s supporters.

O’Donnell has been hosting the show, “The Last Word,” on MSNBC since 2010. He’s been an analyst for the network since 1996. The Harvard College graduate was an aide to the late New York Sen. Daniel Patrick Moynihan and an executive producer on the NBC entertainment series, “The West Wing.”

(AP)