WASHINGTON :  A US Senate Republican has blasted President-elect Donald Trump's criticism of longtime Congressman John Lewis, a Democrat, praising the lawmaker for his leadership in the civil rights movement in the 1960s.

Senator Ben Sasse on Saturday seized on Trump's characterization of Lewis as "All talk, talk, talk - no action," pointing out that his "talk" made a significant contribution in the civil rights movement.

"John Lewis and his 'talk' have changed the world," Sasse tweeted.Lewis, an African-American, was a key civil rights leader in the 1960s as chairman of the Student Nonviolent Coordinating Committee. He was frequently arrested and beaten by police officers at protests, including “Bloody Sunday” in Selma, Alabama, in 1965.

Trump on Saturday targeted Lewis after Congressman Lewis questioned the president-elect's legitimacy.

"I believe in forgiveness. I believe in trying to work with people. It will be hard. It's going to be very difficult. I don't see this president-elect as a legitimate president,” Lewis said in an interview with MSNBC on Friday. He said he won't attend Trump's inauguration on January 20.“I think the Russians participated in helping this man get elected. And they helped destroy the candidacy of Hillary Clinton,” he added.

Trump hit back, accusing Lewis of not doing enough for his district and delivering "no action or result."“Congressman John Lewis should spend more time on fixing and helping his district, which is in horrible shape and falling apart (not to mention crime infested) rather than falsely complaining about the election results. All talk, talk, talk - no action or results. Sad!” Trump wrote in a pair of tweets.

The remarks about the district, which swings through heart of metro Atlanta and includes some of the city’s crown jewels, were roundly criticized by leaders from both sides of the aisle. Jason Carter, the 2014 Democratic candidate for governor who represented part of the 5th District in the state Senate, said Trump “clearly doesn’t know anything about the 5th District or Atlanta.”

“It exemplifies what’s great about this country,” Carter said. “The center of business, the center of innovation and the cradle of the civil rights movement and it’s incredibly successful right now."

Not only that, Trump's response also sparked a flurry of denunciations by Democratic lawmakers. Sasse appears to be the only Republican lawmaker publicly critical of the president-elect's attack so far.

Democratic lawmakers - Jim McGovern, Joe Kennedy, , Katherine Clark, and Stephen Lynch - joined their House collragues in offering their support to the Lewis.

McGovern, who has been an outspoken critic of the president-elect, blasted Trump for going after Lewis in his own series of tweets.

"Here's a tip: Instead of attacking civil rights icons like John Lewis, reach out to all the Americans feeling threatened by your presidency," he wrote to the incoming president on Saturday.

McGovern further said he proud to call the congressman his friend in the fight for progress, adding that "America is stronger because of civil rights heroes like John Lewis."

Pointing to Lewis' history as a civil rights leader, Kennedy argued that if stones and batons couldn't stop the congressman's fight for justice, "petty tweets certainly won't."

Clark called Lewis "an American hero who was willing to sacrifice his life for our democracy." He further accused Trump of being "willing to sacrifice our democracy for his personal enrichment."

Lynch also came to the defence of Lewis, whom he called "a great American."

House Democratic Leader Nancy Pelosi, meanwhile, said it's important to remember Lewis' civil rights background - particularly ahead of Martin Luther King Jr. Day."Ahead of #MLKday2017, let us remember that many have tried to silence @repjohnlewis over the years. All have failed," she tweeted Saturday.

House Democrats also tweeted out their support for the Georgia congressman. "We stand with @repjohnlewis," the caucus tweeted.