Elon Musk has denied claims that he was in contact with Vladimir Putin and had discussed a possible “peace plan” to end the war in Ukraine.

Ian Bremmer, a political scientist and president of the political risk consultancy firm Eurasia Group, told CNN on Tuesday that the Tesla CEO had told him about a conversation he had with Putin, alleging that Putin had told him what would have to happen to end the war:

“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 said.

According to Bremmer, Putin told Musk that he would accomplish those three goals “no matter what” and would use nuclear force if necessary.

Musk responded to Bremmer’s allegations by tweeting, “I have spoken to Putin only once and that was about 18 months ago. The subject matter was space.”

Bremmer repeated his claim on Twitter, writing, “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,” to which Musk responded, “Nobody should trust Bremmer.”

The claims against Musk come a week after he tweeted a “Ukraine-Russia peace plan,” which was welcomed by Moscow, according to the BBC.

“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 not the first time that Musk has been accused of being in contact with the Kremlin. According to CNN, “multiple sources” have said that Musk has had several conversations in the past few weeks about a similar peace plan.

An anonymous source told CNN that Musk alleged that his proposed peace deal was endorsed by the Kremlin.