Elon Musk denies claim he spoke to Vladimir Putin about the war in Ukraine

(CNN) Tesla CEO Elon Musk has denied a claim that he spoke directly to Russian President Vladimir Putin in recent weeks about the war in Ukraine and a proposed "peace plan" to end the conflict.

Speaking to CNN on Tuesday, American political scientist Ian Bremmer, president of political consulting firm Eurasia Group, claimed Musk told him directly about his conversation with Putin last month.

In a tweet Tuesday, however, Musk said he hadn't spoken with Putin in over a year.

"I have spoken to Putin only once and that was about 18 months ago," Musk tweeted. "The subject matter was space."

Bremmer initially declined to comment further on his conversation with Musk -- but later reiterated his claim on Twitter.

"Elon Musk told me he had spoken with Putin and the Kremlin directly about Ukraine. He also told me what the Kremlin's red lines were," Bremmer wrote.

Musk tweeted a succinct response: "Nobody should trust Bremmer."

Eurasia Group is a political risk research and consulting firm that reports on emerging and developed economies. Bremmer, who is often cited by mainstream media, has also been involved with international organizations including the World Economic Forum.

The exchange comes after Musk tweeted a "Ukraine-Russia peace plan" last week that reflected demands Kremlin officials have made repeatedly in recent months, including that Kyiv commit to military neutrality, acknowledge that Crimea is formally part of Russia, and ensure continued water supply to the peninsula annexed by Moscow in 2014.

"Ukraine-Russia Peace: Redo elections of annexed regions under UN supervision. Russia leaves if that is will of the people. Crimea formally part of Russia, as it has been since 1783 (until Khrushchev's mistake). Water supply to Crimea assured. Ukraine remains neutral," Musk tweeted.

"This is highly likely to be the outcome in the end -- just a question of how many die before then," he added. "Also worth noting that a possible, albeit unlikely, outcome from this conflict is nuclear war."

Musk's tweet was welcomed by the Kremlin -- but sparked outrage among Ukrainian government officials, including President Volodymyr Zelensky, who suggested in a tweet that Musk was expressing support for Russia with his proposal.

"F— off is my very diplomatic reply to you," Ukraine's Ambassador to Germany Andrij Melnyk wrote in response to Musk's Twitter thread.

A lawyer for Musk did not immediately return CNN's requests for comment.

In a series of tweets on Tuesday night, Bremmer strongly defended his claim, saying: "I have been writing my weekly newsletter on geopolitics for 24 [years]. I write honestly without fear or favor and this week's update was no different.

"I've long admired Musk as a unique and world-changing entrepreneur, which I've said publicly. He's not a geopolitics expert."

Musk on peace proposals

Multiple sources told CNN separately that in recent weeks, Musk had floated a similar "peace plan" proposal in conversations with attendees at think tanks and conferences, and hinted at having contact with Kremlin officials.

In a conversation at "The Weekend" festival in Aspen, Colorado, last month, Musk told attendees, "I really would encourage Ukraine -- because Ukraine's had some victories recently -- really encourage them to seek peace. This is the time to do it. They don't want to do it, that's for sure. But this is the time to do it. Cause you know everyone wants to seek peace when they're losing but they don't want to seek peace when they're winning. For now."

According to one attendee, Musk added that "in my view the nature of that peace would be: recognizing Crimea as Russia, allowing Luhansk and Donetsk to be independent, quasi-independent republics, and don't block the water to Crimea like they did last time. Russia would accept those terms."

Based on the ideas Musk put forward, according to another source who heard them, it seemed "clear" he had been "in communication with the Kremlin." A third source echoed that, telling CNN Musk had suggested in late September that his proposals for a peace deal were endorsed by the Kremlin.

Musk made similar suggestions for a resolution to tensions between China and Taiwan, telling the Financial Times that some control over the self-governing island could be handed to Beijing in a bid for peace.

"My recommendation...would be to figure out a special administrative zone for Taiwan that is reasonably palatable, probably won't make everyone happy," Musk told the Financial Times in an interview published last week. "And it's possible, and I think probably, in fact, that they could have an arrangement that's more lenient than Hong Kong."

In a note to Eurasia Group subscribers on Monday, Bremmer expanded upon his conversation with Musk, which he said took place about two weeks ago.

"I spoke with Elon two weeks ago, and he told me Putin (in a direct conversation with him) was "prepared to negotiate" (much as I had heard from Shanghai Cooperation Organization members the week before) and had outlined the minimum the Russian President would require to end the war," Bremmer wrote.

"There were three components: (1) Crimea remains Russian, (2) Ukraine accepts a formal status of neutrality, and (3) recognition of Russia's annexations of Luhansk and Donetsk, Kherson control for the water supply to Crimea, and Zaporizhzhia for the land bridge."

Bremmer wrote that Musk told him Putin said he would accomplish those goals "no matter what," and was prepared to retaliate with a nuclear strike should Zelensky try to take back Crimea by force.

"Elon said everything needed to be done to avoid that outcome," Bremmer wrote.

Musk has been providing Starlink systems to Ukraine since early on in the war, allowing Kyiv to maintain internet and communications access in areas cut off by Russian attacks on infrastructure. But according to Bremmer, Musk was spooked in recent weeks by a Ukrainian request to activate Starlink systems in Crimea -- suggesting a potential ground operation -- and refused the request.

"Musk also appeared concerned about more direct threats from Putin," Bremmer wrote. "While he didn't surface anything explicit with me, he did talk about Russian cyber capabilities and Russia's potential to disrupt his satellites."

Asked on Tuesday about the reported Musk-Putin discussion, US National Security Council official John Kirby told reporters that Musk does not speak on behalf of the Biden administration in any conversations he may have with the Russian President.

"I'll let Mr. Musk speak for his conversations. Obviously, he's not representing the United States government in this conversation. So I think I'll let him characterize this. And we'll avoid commenting on the particulars," Kirby said.

Kirby reiterated that Russia started its war in Ukraine "in an unprovoked and illegal way" and "can end it today simply by taking their troops out."

Absent that, Kirby said the United States plans to continue to support Ukraine with capabilities and tools to succeed on the battlefield.

Zelensky, Kirby added, "will get to determine for himself when is the right time to negotiate, and Mr. Zelensky will get to determine for himself and for his country what terms he's willing to consider, what success looks like."

Correction: A previous version of this story incorrectly stated the name of the festival at which Elon Musk told attendees Ukraine should seek peace. It took place at "The Weekend" festival.