Former Vice President Joe Biden said Sunday that Russians have worked to block him from winning the Democratic nomination while favoring Sen. Bernie Sanders, though he admitted his claims were not based on anything he had been told by intelligence officials.

"The Russians don't want me to be the nominee," Biden said on CBS News' "Face the Nation," later adding, "they like Bernie.

Biden made the comment after being asked about Sanders' momentum in the Democratic primary race to determine who will take on President Donald Trump in November.

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After leading in virtually every poll on the national race for his party's nomination for most of 2019, Biden has fallen behind Sanders in most recent polls. And Sanders has won two of the first three primary contests, while Biden has yet to win a state and performed below expectations in Iowa and New Hampshire.

© Mario Tama, Getty Images Democratic presidential candidate former Vice President Joe Biden gestures as Sen. Bernie Sanders, I-Vt., listens during the Democratic presidential primary debate in Las Vegas, Feb. 19. 2020.

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When asked if he could stop Sanders, Biden insisted he was still "the best guy to beat Trump" before claiming the Russians were working against him.

"They spent a lot of money on bots on Facebook and they've been taken down saying Biden is a bad guy. They don't want Biden running," Biden said of the Russians. "No one's helping me to try to get the nomination."

On Friday, The Washington Post first reported that U.S. intelligence officials told Sanders that Russian President Vladimir Putin was interfering in the Democratic primary race and was trying to help his campaign. The Post report did not specify how the Russians were trying to accomplish that goal. But former special counsel Robert Mueller's report on 2016 election interference said Russian intelligence agents used social media as a major part of their effort.

"I don't care, frankly, who Putin wants to be president. My message to Putin is clear: stay out of American elections, and as president I will make sure that you do," Sanders said in response to the report. He acknowledged he was told in an intelligence briefing "about a month ago" about Russia's latest meddling, though he said, "It was not clear what role they were going to play."

Biden called for the other campaigns to be given the same information.

"I have not spoken to the intelligence community, but I think the intelligence community should inform the rest of us who are running what they told Senator Sanders," he said.

When pressed about his claim that Russians had used bots on Facebook to attack him, Biden said he had been told by a campaign staffer that was what had occurred.

"All I know is what I've read and has been reported. Not one has confided in me. I have no inside information," Biden said.

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Sanders also suggested that his supporters who have been accused of inappropriate and aggressive behavior online, often referred to "Bernie Bros, could be part of Russian "internet propaganda to sow division in our country."

"Some of the ugly stuff on the internet attributed to our campaign may well not be coming from real supporters," Sanders said.

Biden appeared unconvinced.

"Well, look, the people that occupied my office, maybe they were Russians. I don't know," Biden said, referring to Sanders supporters who were arrested in January for refusing to leave Biden's Des Moines campaign headquarters. Citing that incident and attacks on the Culinary Workers union after it didn't endorse Sanders, Biden accused the Vermont senator's supporters of engaging in "Trump-like stuff."

"This is not the stuff that we've done in Democratic primaries before," Biden said.

On Friday, The New York Times first reported that Shelby Pierson, an aide to former acting Director of National Intelligence Joseph Maguire, told lawmakers in a Feb. 13 briefing that Russian interference also aimed to help Trump secure his reelection. The Times reported that Trump's anger about the briefing contributed to his decision to replace Maguire.

Trump blasted the reports about Russian interference as "disinformation" at a campaign rally in Las Vegas on Friday.

On Sunday, Trump, without evidence, accused House Intelligence Committee Chairman Adam Schiff, D-Calif., of leaking the briefing's contents to the press. Schiff responded by tweeting that Trump had "betrayed America. Again."

Nice deflection, Mr. President. But your false claims fool no one. You welcomed Russian help in 2016, tried to coerce Ukraine’s help in 2019, and won’t protect our elections in 2020. Now you fired your intel chief for briefing Congress about it. You’ve betrayed America. Again. https://t.co/WlMDaz8stF — Adam Schiff (@RepAdamSchiff) February 23, 2020

"The President is angry because the intelligence community, in fact, informed Bernie Sanders and I guess others and members of the Intelligence Committee that, in fact, the Russians want to see Trump reelected," Biden said. "And they like Bernie."

On Sunday, national security adviser Robert O'Brien said on "Face the Nation" that he had not seen any intelligence to support the leaked details from the briefing regarding Russian election interference.

"There's no briefing that I've received, that the president has received, that says that President Putin is doing anything to try and influence the elections in favor of President Trump. We just haven't seen that intelligence," O'Brien said.

O'Brien said he understood why the Russians would favor Sanders, who would "spend money on social programs and probably would have to take it out of the military." But he did not see why Russia would want Trump reelected.

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"Why would they have a preference for President Trump, who is rebuilding our military, who is giving the Ukrainians lethal aid to fight Russian troops?" O'Brien asked. "That doesn't make sense."

Sen. Chris Murphy, D-Conn., said on CNN's "State of the Union" that O'Brien "should stay out of politics."

"Of course, it stands to reason that they want Donald Trump reelected, because he has been a gift to Russia," Murphy said. "He has essentially ceded the Middle East to Russian interests. He has accomplished more in the undermining of NATO than Russia has in the last 20 years. And he continues to effectively deny that they have an ongoing political operation here in the United States that, by and large, is intended to support Donald Trump and his allies."

Though O'Brien insisted the administration has done everything it can to prevent foreign election interference, Biden agreed with Murphy's assessment.

"Every intelligence agency has told them they continue to be engaged in this activity," Biden said of the administration's response to Russian meddling. "There is not any question anymore. There's never been a question for the last three years. And what's he doing? Zero. What is the Republican leadership in the United States Senate and Congress doing? Zero."

Contributing: Christal Hayes

This article originally appeared on USA TODAY: 'They like Bernie': Biden says Russia working to prevent him from getting nomination