Russian President Vladimir Putin did not take too kindly Joe Biden calling him a“war criminal.” The Russian leader jabbed back at Biden, mocking him for his “irritability, fatigue and forgetfulness.”

The Daily Caller reports:

Top Russian presidential spokesman Dmitry Peskov said Russia sees and hears the statement that Biden made, and considers it a “personal insult” to Putin, but won’t take the accusation seriously, according to Russia media outlet TASS.

“Bearing in mind Mr. Biden’s irritability, fatigue and forgetfulness, which eventually results in aggressive statements, we will possibly prefer to refrain from making any strong comments so as not to trigger more aggression,” Peskov continued.

Biden called Putin a “war criminal” Wednesday for invading Ukraine in response to Fox News White House correspondent Jacqui Heinrich’s question.

He then said Putin was a “murderous dictator, a pure thug who is waging an immoral war against the people of Ukraine,” while speaking at the Friends of Ireland Luncheon on St. Patrick’s Day at Capitol Hill on Thursday.