Vladimir Putin is a “crazy SOB,” President Joe Biden said Wednesday — a direct stab at the Russian leader that drew a furious reaction from the Kremlin.

In comments at a fundraiser in San Francisco, Biden also took aim at former President Donald Trump, ridiculing his likely opponent in the November presidential election for comparing himself to Russian opposition leader Alexei Navalny, who died last week.

Discussing climate change, Biden also made a brief diversion to note that the world should be worried about Putin’s repeated nuclear threats against the West.

“We have a crazy SOB, that guy Putin and others and we always have to be worried about a nuclear conflict,” he said. “But the existential threat to humanity is climate.”

In response, the Kremlin criticized Biden for what it described as a poor attempt to sound like a “Hollywood cowboy.”

“The use of such language against the head of another state by the president of the United States is unlikely to infringe on our president, President Putin,” Kremlin spokesman Dmitry Peskov said. “But it debases those who use such vocabulary.”

In later comments to a state television reporter, Peskov added: “This is a disgrace for the country itself, I mean the United States.”

Biden has a tendency to go off script during election fundraisers and in recent months has used these more informal events to criticize China, the Republican Party and U.S. ally Israel.

But in recent days he has also stepped up his criticism of Trump, particularly in regard to his approach to Putin.

At the fundraiser Wednesday night, Biden criticized Trump for likening his situation to that of Navalny, whose death in an Arctic penal colony has seen Biden and other Western leaders point the finger at the Kremlin.

“He’s comparing himself to Navalny and saying that because our country has become a communist country” he has been “persecuted just like Navaly was persecuted — where the hell does this come from,” he said. “If I stood here 10, 15 years ago and said this you all would have thought that I should be committed — it’s astounding.”

The Kremlin has denied involvement in Navalny’s death and criticized the U.S. and others for what it said was a rush to judgment before any facts are known. Navalny’s family has accused Putin of holding his body as part of a cover up.

The Biden administration is set to announce a major sanctions package Friday to hold Russia accountable.

Also at the San Francisco fundraiser, Biden said that nine heads of state from other countries had urged him to defeat Trump for the sake of democracy.

“As I walk out of meetings, a head of state will find an excuse to come up close and say: ‘You’ve got to win.’ Not because I’m so special,” he said. “You’ve got to win because my democracy is at stake if the other guy wins,” he added, recalling the conversations.

Biden also suggested that the current generation of Republican congressmen and women were “worse” than racist, segregationist lawmakers that he served with in the past.

“I’ve served with real racists; I’ve served with Strom Thurmond,” the president said referring to the former pro-segregation Senator from South Carolina. “I’ve served with all these guys that have set terrible records on race. But guess what? These guys are worse,” he added. referring to current Republicans. “These guys do not believe in basic democratic principles.”

Biden, 81, who is facing questions about his age and memory, has a history of using blunt words when it comes to other world leaders.

In 2021, he agreed with an interviewer that Putin was a “killer” and last year labeled Chinese President Xi Jinping a “dictator” — comments that caused a considerable degree of diplomatic fallout.

Putin said last week that his country would prefer to see the “more experienced” Biden in the White House for a second term than Trump.