Trump calls Putin 'crazy,' warns of Russia's 'downfall'

White House press secretary Karoline Leavitt was asked on Monday if President Donald Trump has spoken to former President Joe Biden directly following Biden's prostate cancer diagnosis.

"Not to my knowledge, I don't believe they have spoken, but I'm sure the president would be open to doing that," Leavitt said. "I spoke to him last night about the former president's cancer diagnosis and the statement that he put out was the initial reaction he had with me on the phone as well."

Trump wrote on his conservative social media platform on Sunday, "Melania and I are saddened to hear about Joe Biden's recent medical diagnosis. We extend our warmest and best wishes to Jill and the family, and we wish Joe a fast and successful recovery."

White House press secretary Karoline Leavitt, at Monday morning's briefing, told reporters the public can expect to hear from President Donald Trump or the White House following his calls today regarding the Russia-Ukraine war.

Trump will be speaking with Russia's Vladimir Putin at 10 a.m. ET. Leavitt said Trump is planning to call Ukrainian President Volodymyr Zelenskyy immediately after that conversation.

"I don't want to get ahead of those very important conversations, but of course you will hear directly from the president or me after those calls conclude today, so you can expect that," she said.

ABC News Senior Political Correspondent Rachel Scott pressed Leavitt if Trump would set a new deadline for peace talks on the call, but Leavitt repeated she wouldn't speak ahead of Trump on any specific timeline.

"His goal is to see a ceasefire and to see this conflict come to an end, and he's grown weary and frustrated with both sides of the conflict," she said.

Asked if Trump is open to meeting with Putin, Leavitt said she believed Trump "would certainly be open to that but let's see how this call goes today."

President Donald Trump early on Monday said he would call for an investigation into musician Bruce Springsteen's endorsement of former Vice President Kamala Harris' presidential run.

"I am going to call for a major investigation into this matter," Trump said in a post on his Truth Social network. "Candidates aren't allowed to pay for ENDORSEMENTS, which is what Kamala did, under the guise of paying for entertainment."

Springsteen preformed at Harris' campaign appearance in Georgia in October. Trump in his Monday post asked how much Harris had paid the musician.

His call for a probe followed a back-and-forth between the president and the songwriter last week.

As he took the stage in Manchester, England, last Wednesday, Springsteen had called "upon the righteous power of art, of music, of rock and roll, in dangerous times."

"In my home, the America I love, the America I've written about, that has been a beacon of hope and liberty for 250 years is currently in the hands of a corrupt, incompetent, and treasonous administration," Springsteen said.

He added, "Tonight we ask all who believe in democracy and the best of our American experiment to rise with us, raise your voices against authoritarianism and let freedom ring!"

Trump in a subsequent post on Truth Social called Springsteen "overrated" and said he shouldn't speak about America "until he gets back into the Country."

President Donald Trump is expected to speak with Russian President Vladimir Putin at around 10 a.m. ET on Monday, as the White House continues its push for an end to Moscow's 3-year-old invasion of Ukraine after last week's peace talks in Istanbul, Turkey.

"The subjects of the call will be, stopping the 'bloodbath' that is killing, on average, more than 5,000 Russian and Ukrainian soldiers a week, and trade," Trump wrote in a post to his Truth Social website on Saturday.

"I will then be speaking to President Zelenskyy of Ukraine and then, with President Zelenskyy, various members of NATO," Trump added.

Renewed direct contact with Putin -- the last publicly known direct phone call between the two presidents took place in February -- comes after Trump's hopes for peace talks progress in Istanbul were scuppered, Putin having declined to attend despite Ukrainian President Volodymyr Zelenskyy's invitation to do so.

The Istanbul talks were the first known meeting between representatives of Moscow and Kyiv since spring 2022, when the Turkish city hosted the final round of unsuccessful peace negotiations to end Russia's unfolding invasion.
Once it became clear Putin would not attend, Trump told reporters of the peace effort, "Nothing's going to happen until Putin and I get together, okay?"

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-ABC News' David Brennan