Republican Governor Tate Reeves on Tuesday signed the historic bill that takes the 126-year-old state flag out of law, immediately removing official status for the banner that has been a source of division for generations.

"This is not a political moment to me but a solemn occasion to lead our Mississippi family to come together, to be reconciled, and to move on," Reeves said in a statement.

"We are a resilient people defined by our hospitality. We are a people of great faith. Now, more than ever, we must lean on that faith, put our divisions behind us, and unite for a greater good."

Mississippi has faced increasing pressure to change its flag since protests against racial injustice have focused attention on Confederate symbols.

A broad coalition of legislators on Sunday passed the landmark legislation to change the flag, capping a weekend of emotional debate and decades of effort by black lawmakers and others who see the rebel emblem as a symbol of hatred.

The Confederate battle emblem has a red field topped by a blue X with 13 white stars. White supremacist legislators put it on the upper-left corner of the Mississippi flag in 1894, as white people were squelching political power that African Americans had gained after the Civil War.

Critics have said for generations that it's wrong for a state where 38 per cent of the people are black to have a flag marked by the Confederacy, particularly since the Ku Klux Klan and other hate groups have used the symbol to promote racist agendas.

Mississippi voters chose to keep the flag in a 2001 statewide election, with supporters saying they saw it as a symbol of Southern heritage. But since then, a growing number of cities and all the state's public universities have abandoned it.

Several Black legislators, and a few white ones, kept pushing for years to change it. After a white gunman who had posed with the Confederate flag killed Black worshipers at a South Carolina church in 2015, Mississippi's Republican speaker of the House, Philip Gunn, said his religious faith compelled him to say that Mississippi must purge the symbol from its flag.

The issue was still broadly considered too volatile for legislators to touch, until the police custody death of an African American man in Minneapolis, George Floyd, set off weeks of sustained protests against racial injustice, followed by calls to take down Confederate symbols.

A groundswell of young activists, college athletes and leaders from business, religion, education and sports called on Mississippi to make this change, finally providing the momentum for legislators to vote.

Australian Associated Press