Former Florida governor and 2016 presidential candidate Jeb Bush endorsed a Senate run by Mitt Romney on Monday.

“Mitt would make a phenomenal addition to the U.S. Senate. I hope he runs,” Bush tweeted, sharing a tweet from Romney.

In his own tweet, Romney, the 2012 Republican presidential nominee, denounced comments President Trump made during a bipartisan meeting with senators last week on an immigration deal. During the gathering, Trump referred to El Salvador, Haiti and African nations as "shithole countries."

"The poverty of an aspiring immigrant’s nation of origin is as irrelevant as their race. The sentiment attributed to POTUS is inconsistent w/ America’s history and antithetical to American values. May our memory of Dr. King buoy our hope for unity, greatness, & 'charity for all,'" Romney tweeted Monday.

Romney has reportedly said in private he intends to run for the Senate seat currently held by Sen. Orrin Hatch, R-Utah. Hatch announced earlier this month he will retire at the end of his current term.

The outgoing senator also said he would endorse Romney, if he decided to run for his seat.

Romney hasn’t been shy in hiding his criticism of Trump, though the two talked after Hatch announced he wouldn’t run for re-election.

Trump reportedly urged Romney to mount a Senate bid.