(CNN) President Joe Biden said in an exclusive CNN interview Tuesday he believed Russian President Vladimir Putin is a "rational actor" who nonetheless badly misjudged his ability to invade Ukraine and suppress its people.
"I think he is a rational actor who has miscalculated significantly," Biden told Jake Tapper as Russian bombardments on civilian targets in Ukraine signaled another turning point in the months-long war.
Coming as the conflict in Ukraine approaches its eighth month, the interview with Biden provided fresh insight into his thinking as top US officials watch the fighting unfold in Ukraine with escalating concern.
Biden, who warned last week the risk of "nuclear Armageddon" was at its highest level in 60 years, said in the interview that threats emanating from Russia could result in catastrophic "mistakes" and "miscalculation," even as he declined to spell out how precisely the United States would respond if Putin deploys a tactical nuclear device on the battlefield in Ukraine.
And he said there would be "consequences" for Saudi Arabia after it partnered with Moscow to announce a cut in oil production, a move that could cause gas prices to increase as November's midterm elections approach.
Biden, his top officials and fellow Western leaders have spent the past several months debating what steps Putin may take as his troops suffer embarrassing losses on the battlefield in Ukraine.
Whether Putin is acting rationally has been a subject of intense debate as leaders work to predict his next steps. While Biden said Tuesday he believed Putin himself was rational, he characterized the Russian leader's aims in Ukraine -- which Putin laid out in an angry speech as he launched the war in February -- as ridiculous.
"You listen to what he says. If you listen to the speech he made after when that decision was being made, he talked about the whole idea of -- he was needed to be the leader of Russia that united all of Russian speakers. I mean, it's just I just think it's irrational," Biden said.
Going further, Biden said Putin wrongly believed Ukrainians would submit to Russian invasion -- a misjudgment that's been disproved by fierce resistance inside the country.
"I think the speech, his objectives were not rational. I think he thought, Jake, I think he thought he was going to be welcomed with open arms, that this was the home of Mother Russia in Kyiv, and that where he was going to be welcomed, and I think he just totally miscalculated," Biden said.
Indeed, a counteroffensive launched by Ukraine last month was successful in retaking territory previously held by the Russians, including critical transportation hubs. The losses proved the latest major embarrassment for Russia, whose military has struggled over the course of the seven-month war.
This week, however, Russia launched one of its fiercest bombing campaigns since invading in late February. At least 19 people have been killed and more than 100 wounded across the country, as far away as the western city of Lviv, hundreds of miles from the war's main theaters in eastern and southern Ukraine.
Asked whether he would meet Putin at next month's Group of 20 summit in Indonesia, Biden said he didn't see a good reason for a sit-down.
"It would depend on specifically what he wanted to talk about," Biden said, adding if Putin wanted to discuss the jailed American basketball star Brittney Griner then he would be open to talking.
"But look, he's acted brutally, he's acted brutally," Biden said. "I think he's committed war crimes. And so I don't, I don't see any rationale to meet with him now."
After Biden warned last week the risk of nuclear "Armageddon" was at its highest point since the Cuban Missile Crisis, he told Tapper he didn't believe Putin would ultimately take that step.
"I don't think he will," Biden said when asked by Tapper whether the Russian leader would use a tactical nuclear weapon -- a prospect US officials have watched with concern as Russian troops suffer embarrassing losses on the battlefield.
"I think it's irresponsible for him to talk about it, the idea that a world leader of one of the largest nuclear powers in the world says he may use a tactical nuclear weapon in Ukraine," Biden added.
Biden said even Putin's threats have a destabilizing effect, and warned of the potential errors in judgment that could ensue.
"The whole point I was making was it could lead to just a horrible outcome," he told Tapper. "And not because anybody intends to turn it into a world war or anything, but just once you use a nuclear weapon, the mistakes that can be made, the miscalculations, who knows what would happen."
"He, in fact, cannot continue with impunity to talk about the use of a tactical nuclear weapon as if that's a rational thing to do," Biden added later. "The mistakes get made. And the miscalculation could occur, no one can be sure what would happen and could end in Armageddon."
Biden refused to disclose what a US response would look like should Putin follow through on his nuclear threats. But he said the Department of Defense had proactively developed contingencies should the scenario come to pass.
"What is the red line for the United States and NATO, and have you directed the Pentagon and other agencies to game out what a response would be if he did use a tactical nuclear weapon or if he bombed the Zaporizhzhia nuclear power plant in Ukraine or anything along those lines?" Tapper asked.
"There's been discussions of that, but I'm not going to get into that. It would be irresponsible of me to talk about what we would or wouldn't do," Biden said.
"Have you asked the Pentagon to game it out, though?" Tapper asked.
"The Pentagon didn't have to be asked," Biden said.
Biden spoke to Tapper a few hours after meeting virtually with members of the Group of 7 industrialized nations, who heard from Ukrainian President Volodymyr Zelensky on the need to bolster his country's air defenses amid the new Russian bombardments.
Zelensky told the meeting that "common efforts to create an air shield for Ukraine" must be intensified amid a barrage of Russian cruise missile and drone attacks.
White House officials have said the US is prepared to further bolster Ukraine's air defenses, including through missile defense systems that Biden expedited delivery of over the summer.
Yet Russia's intense aerial assault of the Ukrainian capital Kyiv and on civilian infrastructure suggested Putin could be employing new tactics meant to terrorize Ukrainians as the winter approaches.
Biden told Tapper he believed it was time to "rethink" the US relationship with Saudi Arabia after the kingdom partnered with Russia to cut oil production, a rebuke after intensive White House efforts to prevent such a decision.
"I am in the process, when the House and Senate gets back, they're going to have to -- there's going to be some consequences for what they've done with Russia," Biden said.
The decision by the Saudi-led OPEC+ oil cartel to cut production last week prompted anger at the White House, where officials said Biden was personally disappointed by what they called a "shortsighted" decision.
The move, which came three months after Biden visited Saudi Arabia and met its de facto leader Crown Prince Mohammed bin Salman, has the potential to raise gas prices in the weeks ahead of November's midterm elections.
"Let's get straight why I went," Biden said. "I didn't go about oil, I went about making sure that we made sure that we weren't going to walk away from the Middle East."
After reaching highs over the summer, gas prices had been steadily decreasing, providing Biden and his top aides a potent talking point in the lead-up to the elections.
But a combination of factors, including rising demand and maintenance at some US refineries, has caused prices to begin ticking back up. The OPEC+ decision is poised to aggravate those factors.
For Biden, the decision was a particular affront because of his efforts over the summer to repair ties with Saudi Arabia, despite the kingdom's woeful human rights record and bin Salman's role in the murder of dissident journalist Jamal Khashoggi.
This story has been updated with more from the interview with Biden.