Biden tells David Muir that Putin’s suspension of the nuclear treaty with the US is a “big mistake”

President Joe Biden told ABC News anchor David Muir in a new interview that it was a “big mistake” for Russian President Vladimir Putin to temporarily suspend Russia’s participation in the last remaining nuclear weapons treaty between the two countries.

“It’s a big mistake to do that. Not a big responsibility. But I don’t read that he’s considering using nuclear weapons or anything like that,” Biden told Muir in Poland on Wednesday, before the president returned to Washington.

Biden said he’s “not sure what else it is.” [Putin] He was able to say it in his speech at the moment, but I think it’s wrong and I’m sure we’ll be able to work it out.”

Putin announced on Tuesday that Russia would suspend its participation in the New START treaty, first signed in 2010 and extended in 2021, which applies caps to the number of nuclear weapons each country deploys and inspections of nuclear sites.

The Russian president said he was temporarily suspending participation in the agreement because of the support of the United States and other NATO allies for Ukraine, which has been fending off Moscow’s brutal invasion for nearly a year.

“They want to inflict a ‘strategic defeat’ on us and try to get access to our nuclear facilities at the same time,” Putin said in a speech on Tuesday, repeating a phrase used by US officials to describe the desired outcome in Ukraine.

Putin insisted that Russia would not withdraw from the agreement entirely, and the Russian Foreign Ministry said the ceiling on nuclear weapons would continue to be respected. But the decision nevertheless upset Washington, with Secretary of State Antony Blinken calling it “deeply unfortunate and irresponsible” on Tuesday.

“I think it’s important that we continue to operate responsibly in this region,” Blinken told reporters. “It’s also something the rest of the world expects of us.”

This week, Biden made a surprise visit to Kiev, Ukraine, before building support among allies in Poland to continue aid to the war-torn country.

And Biden said in Warsaw: “The appetite of a tyrant cannot be appeased, it must be opposed. Tyrants only understand one word, ‘No!’ “. “no no no. You will not take my country. No, you will not take my freedom. No, you will not take my future.”

For more of Muir’s interview with President Biden, watch “World News Tonight with David Muir” on ABC at 6:30 p.m. ET.