Mitt Romney took a swipe at Donald Trump on Monday, condemning the crude comments the president was said to have made about Haiti and African countries -- calling them “inconsistent (with) America’s history and antithetical to American values” with a reference to Martin Luther King, Jr.

“The poverty of an aspiring immigrant’s nation of origin is as irrelevant as their race,” Romney tweeted. “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.’”

On Thursday, sources said Trump questioned why the U.S. should permit immigrants from “s---hole countries” during negotiations with a bipartisan group of senators.

Neither Trump nor the White House initially denied making the comments, though 24 hours later, Trump tweeted to his 46.7 million followers that he had never made the derogatory remarks.

Illinois Democratic Sen. Dick Durbin, who was present at the Trump meeting, released a statement saying he had heard the president make the comments himself. South Carolina Republican Sens. Tim Scott and Lindsey Graham suggested the reporting of Trump’s remarks was “basically accurate.”

Romney’s tweet on Martin Luther King Day underscores the one-time GOP presidential candidate and potential Utah senate candidate’s resistance to Trump.

Romney has taken Trump to task over his handling of the Charlottesville, Va., race-based riots.

“Whether he intended to or not, what (Trump) communicated caused racists to rejoice, minorities to weep, and the vast heart of America to mourn,” Romney wrote on Facebook last August. “His apologists strain to explain that he didn’t mean what we heard.”

Then, in December, Romney rebuked Alabama Republican Senate candidate Roy Moore, whom Trump had supported. Moore ultimately lost to the Democrat, Doug Jones.

“Roy Moore in the US Senate would be a stain on the GOP and on the nation. Leigh Corfman and other victims are courageous heroes. No vote, no majority is worth losing our honor, our integrity,” Romney tweeted in reference to the women who accused Moore of sexual assault and misconduct.