U.S. Rep. John Lewis says he won't attend the opening of the Mississippi Civil Rights Museum, calling it intolerable that President Donald Trump is slated to appear.

The Georgia Democrat and civil rights icon made the announcement Thursday afternoon, adding that he would reconsider only if Trump decides not to attend, according to the Atlanta Journal-Constitution.

“Right now we’re not going,” Lewis told the newspaper. “But there’s a possibility that the head man may not show up, may cancel.”

The lawmaker’s recent comments came one day after he first expressed doubts about appearing on the same program as the president. “I think his presence would make a mockery of everything that people tried to do to redeem the soul of America and to make this country better,” Lewis said in comments on Wednesday.

Several prominent Mississippi Democrats say they won't attend. Some plan protests. Lewis’ house colleague, Bennie Thompson, D-Miss., said he would not attend.

In a joint statement, Lewis and Thompson explained their decision.

"Right now we’re not going. But there’s a possibility that the head man may not show up, may cancel." — Rep. John Lewis

"Trump’s attendance and his hurtful policies are an insult to the people portrayed in this civil rights museum. The struggles represented in this museum exemplify the truth of what really happened in Mississippi,” reads the statement. “President Trump’s disparaging comments about women, the disabled, immigrants and National Football League players disrespect the efforts of Fannie Lou Hamer, Aaron Henry, Medgar Evers, Robert Clark, James Chaney, Andrew Goodman, Michael Schwerner and countless others who have given they're all for Mississippi to be a better place."

The White House responded to the statement late Thursday afternoon. “We think it’s unfortunate that these members of Congress wouldn’t join the president in honoring the incredible sacrifice civil rights leaders made to right the injustices in our history,” Press Secretary Sarah Sanders said. “The president hopes others will join him in recognizing that the movement was about removing barriers and unifying Americans of all backgrounds.”

The Saturday ceremony marks Mississippi's bicentennial of admission to the Union. But what was intended as a moment of racial unity and atonement in the state where some four in 10 residents are African-American is descending into racial and partisan strife after Gov. Phil Bryant invited fellow Republican Trump to attend.

The NAACP has said Trump should cancel his planned appearance because of his divisive record on civil rights issues.

“President Trump’s statements and policies regarding the protection and enforcement of civil rights have been abysmal, and his attendance is an affront to the veterans of the civil rights movement,” NAACP President Derrick Johnson said in a statement on Wednesday. “He has created a commission to reinforce voter suppression, refused to denounce white supremacists, and overall, has created a racially hostile climate in this nation.”