 U.S. President Joe Biden referred to Russian President Vladimir Putin as a crazy SOB during a fundraising event in San Francisco. We have a crazy SOB that guy, Putin, others. And we always have to be worried about a nuclear conflict. But the existential threat to humanity is climate, Biden said, addressing those present at the charity evening.Biden's verbal attacks against Putin have also sharply intensified at the White House and on the campaign trail. Last week, the U.S. president blamed Putin and his thugs for the death of opposition leader Alexei Navalny. We don't know exactly what happened, but there is no doubt that the death of Navalny was a consequence of something that Putin and his thugs did, Biden said at the White House after Russian prison officials announced that Navalny had died, the Kremlin has denied involvement in Navalny's death and said Western claims that Putin was responsible or unacceptable. Biden also criticized comments by former President Donald Trump, who likened his legal troubles to the death of Alexei Navalny. The American president paraphrased his predecessor's comments and said that if I stood here 10 to 15 years ago and said all this, you'd all think I should be committed. He's comparing himself to Navalny and saying that because our countries become a communist country, he was persecuted, just like Navalny was persecuted. Where the hell does this comes from, Biden said, according to journalists present in the room.