Sen. Marco Rubio, R-Fla., jokingly suggested President Biden undergo diversity training for his "unconscious bias" on Thursday after the president used the phrase "Neanderthal thinking" to describe Texas and Mississippi rolling back coronavirus restrictions. 

The Florida Republican quipped that the president’s "use of an old stereotype" when referring to the decision by some conservative states to lift mask mandates and reopen their economies was "hurtful" to those who share Neanderthalian genes.

"President Biden’s use of an old stereotype is hurtful to modern Europeans, Asians & Americans who inherit about 2% of their genes from Neanderthal ancestors," wrote Rubio, who linked out to an article in the tweet.

Rubio suggested Biden "seek training on unconscious bias" and called on the president to "apologize for his insensitive comments."

TEXAS LT. GOV SLAMS BIDEN'S 'NEANDERTHAL THINKING' COMMENT ON LIFTING COVID RESTRICTIONS

Rubio’s tweet came after Biden’s Wednesday comments, where he took a shot at Republican governors in Texas and Mississippi for lifting mask mandates.

The president called the decision by the states "Neanderthal thinking" – a comment that has received massive backlash from Republicans both online and on the air.

Sen. Ted Cruz, R-Texas, chimed in on Rubio’s tweet on Thursday, joking: "Some of us are a lot more than 2 percent!"

Fox News analyst and former White House press secretary Kayleigh McEnany blasted Biden during a Thursday "Fox and Friends" appearance, where she compared the comment to former Secretary of State Hillary Clinton’s infamous "basket of deplorables" comment.

CLICK HERE TO GET THE FOX NEWS APP

White House press secretary Jen Psaki defended Biden’s comments, saying they were a "reflection" of the president’s "frustration and exasperation" and denied the Biden administration had called the governors Neanderthals.  

"The behavior of a Neanderthal, just to be very clear. The behavior of," she emphasized.