Speaker Nancy Pelosi on Friday left open the possibility of House action to punish Representative Steve King over his history of inflammatory remarks as the Iowa Republican's recent defence of white nationalism created a firestorm.

"We'll see what we do about Steve King, but nonetheless nothing is shocking anymore, right?" Ms Pelosi, D-Calif, told reporters. "The new normal around here is to praise white nationalism as something that shouldn't be shunned."

Mr King, who won a ninth term in Congress in November, lamented in an interview with the New York Times that the term had become a pejorative one.

"White nationalist, white supremacist, Western civilization – how did that language become offensive?" Mr King said in the interview, which was published on Thursday.

Mr King later issued a statement and addressed the issue in a speech on the House floor on Friday in which he sought to walk back his remarks. He said he rejects "those labels and the evil ideology that they define" and proclaimed himself "simply a Nationalist."

A number of Democrats are calling on House leaders to consider a resolution to censure Mr King, a vote that would put Republicans on record.

"The US House of Representatives must censure Representative Steve King for his racist remarks," Representative Tim Ryan, D-Ohio, tweeted and added: "Support for white supremacist ideology should have no place in Congress."

Questioned whether she would take action, Ms Pelosi said, "I'm not prepared to make any announcement about that right now, but needless to say there is interest in doing something."

Republican leaders on Thursday stepped forward to criticise Mr King, breaking their months-long silence.

Mr King's interview prompted a rebuke from Representative Liz Cheney, R-Wyo, the number three Republican in the House, who said in a tweet on Thursday morning, "These comments are abhorrent and racist and should have no place in our national discourse."

She was soon followed by House Minority Whip Steve Scalise, R-La, who told reporters in a pen-and-pad that it was "offensive to try to legitimise those terms." But Mr Scalise also praised Mr King's later statement.

"I think it was important that he rejected that kind of evil, because that's what it is. It's evil ideology," Mr Scalise said.

House Minority Leader Kevin McCarthy, R-Calif, also issued a statement on Thursday evening in which he sharply criticised Mr King's comments to the Times.

"Everything about white supremacy and white nationalism goes against who we are as a nation," Mr McCarthy said. "Steve's language is reckless, wrong, and has no place in our society. The Declaration of Independence states that 'all men are created equal.' That is a fact. It is self-evident."

John Oliver discusses Parent Company AT&T Backing ‘White Nationalist’ Steve King for years

Both Mr McCarthy and Mr Scalise were silent in October when asked for comment on incendiary remarks Mr King had made then. At the time, Representative Steve Stivers, R-Ohio, then the chairman of the National Republican Congressional Committee, was the only member of House GOP leadership to rebuke Mr King. (Ms Cheney had not yet been elected to her position as conference chair.)

Mr King has a long history of incendiary remarks on race and immigration throughout his time in Congress. In 2017, Mr King was widely criticised after he declared in a tweet he agreed with far-right Dutch politician Geert Wilders that "our civilization" cannot be restored "with somebody else's babies."

The lawmaker's actions drew increased scrutiny in the wake of last year's mass shooting at a Pittsburgh synagogue. The massacre, in which 11 people were killed, was the deadliest attack on Jews in the United States.

In June, Mr King prompted criticism when he retweeted a message sent by Mark Collett, a self-described "Nazi sympathizer." Mr King declined to delete the retweet.

Then, in the fall, Mr King tweeted his support for Faith Goldy, a white nationalist who ran unsuccessfully for Toronto mayor. The Washington Post also reported Mr King had met in August with members of a far-right Austrian party with historical Nazi ties and declared "Western civilization is on the decline."

Despite losing the support of several corporate donors, including Land O'Lakes and Intel, Mr King still bested his Democratic opponent, J D Scholten, in November.

The 2020 election may be a more challenging one for Mr King, however.

On Wednesday, Iowa State Senator Randy Feenstra announced he will run against King in the Republican primary.

And Iowa Governor Kim Reynolds, R, who backed Mr King during the last campaign and appeared with him on the campaign trail, has said she will not endorse him this time, telling an NBC affiliate in Des Moines that "the last election was a wake-up call for it to be that close."

Asked on Thursday whether the national party will back Mr King in 2020, Mr Scalise declined to weigh in.

"I have no idea what's happening in terms of primaries right now," he said.