In a video released by the Kremlin, President Putin responded to President Biden calling him a "crazy son of a bi**h." This came after Putin praised Biden over Trump as the preferable U.S. president for Russia.
Putin saw Biden's harsh words as a natural reaction, saying, "And judging from what he has just said, I am absolutely right. Because this is a reasonable response to what I have said.
Why? Because he couldn't just tell me: 'Well done, Vladimir, thank you, you’ve helped me a lot"
Despite the insult, Putin mentioned he hasn't changed his opinion and still views Biden as a favorable choice for Russia.
Background information reveals that Biden's comment was made during a public speech, which the Kremlin criticized heavily. There are also reports of Biden using strong language privately, especially regarding Donald Trump.