Russian President Vladimir Putin is a “rational man who made a big miscalculation,” US President Joe Biden said in an interview with CNN, which released several quotes ahead of its full broadcast on Tuesday.

“I think he’s a rational person who made a big miscalculation,” Biden said.

Biden said that Putin mistakenly believed that Ukrainians would submit when Russia invaded Ukraine, a misjudgment that was belied by furious resistance inside the country.

“I believe that his speech, his goals were not rational. I think he thought, I think he thought he would be welcomed with open arms, that this is the home of Mother Russia in Kyiv, and he would be welcomed, and I think he miscalculated,” Biden said.

The counteroffensive launched by Ukraine last month was successful in recapturing territory previously captured by the Russians, including critical transport hubs. These losses were the latest embarrassment for Russia in this war launched by Putin on February 24.

However, this week Russia carried out one of its most brutal attacks since the invasion in late February. At least 19 people have been killed and more than 100 injured across the country in what Vladimir Putin has called revenge after the Kerch Bridge was heavily damaged by an explosion.

US President Joe Biden promised Ukrainian President Volodymyr Zelensky on Monday that Washington would provide modern air systems after Russia’s devastating missile strike on several cities.

So far, the United States has approved the shipment of eight advanced NASAMS systems to Ukraine, with two expected to be delivered in the near future and six more in the longer term.

“We believe we are on the verge of delivering the first two in the near future,” White House spokesman John Kirby said during a press briefing. “Of course, we are interested in the fastest possible delivery of NASAMS to Ukraine.”