Liz Cheney says G.O.P. must ‘make clear that we aren’t the party of white supremacy.’

Representative Liz Cheney of Wyoming, the No. 3 House Republican, on Tuesday called on her party to “make clear that we aren’t the party of white supremacy,” arguing that elected Republicans must forcefully condemn those responsible for the Jan. 6 riot at the Capitol.

“It’s very important for us to ignore the temptation to look away,” from the attack, Ms. Cheney said during a virtual foreign policy event hosted by the Reagan Institute. “It’s very important, especially for us as Republicans, to make clear that we aren’t the party of white supremacy.”

“You saw the symbols of Holocaust denial, for example, at the Capitol that day; you saw the Confederate flag being carried through the rotunda, and I think we as Republicans in particular, have a duty and an obligation to stand against that, to stand against insurrection.”

The remarks by Ms. Cheney, the only Republican leader to vote to impeach former President Donald J. Trump for inciting the insurrection on Congress that left 6 dead, are some of the most forceful comments yet to come from party leaders in the aftermath of the riot. And they cemented what had long been assumed: that despite facing internal rebukes and political blowback at home for her unsparing indictment of Mr. Trump’s role in the insurrection, Ms. Cheney has no intention of moderating her criticism of the former president.

Allies of Mr. Trump were infuriated by Ms. Cheney’s decision last month to vote to impeach him. In Wyoming, the state Republican Party censured her, citing the vote, and called on her to resign.

Some Republicans in Congress retaliated by forcing an internal conference vote in a bid to strip her of her leadership position. Ms. Cheney ultimately held onto her leadership post in a lopsided secret-ballot vote, despite refusing to apologize for voting to impeach Mr. Trump.

On Tuesday she redoubled her criticism of Mr. Trump’s role in the Jan. 6 riot, calling his blasé response while lawmakers were under attack an “existential threat to who we are” that “can’t be minimized or trivialized, and it can never happen again.”

Ms. Cheney also assailed the “America First” foreign policy Mr. Trump and his allies in Congress had championed, calling the ideas behind them “just as dangerous today as they were in 1940 when isolationists launched the America First movement to appease Hitler and prevent America from aiding Britain in the fight against the Nazis.”

“Isolationism was wrong and dangerous then and it is wrong and dangerous now,” she said.

She also extended her criticism to media outlets that falsely reported that the presidential election was fraudulent or stolen, accusing them of “contributing to a very dangerous set of circumstances.”

Her comments were in sharp contrast to those made by her fellow House Republican leaders. Representative Steve Scalise of Louisiana, the No. 2 Republican, on Sunday refused to concede that the election was not “stolen” from Mr. Trump, arguing simultaneously that President Biden was the “legitimate” president but that several states did not administer their election laws correctly. Representative Kevin McCarthy of California, the Republican leader, has offered a series of shifting comments around whether Mr. Trump bears responsibility for the riot.

Republican lawmakers “who take our oaths and obligations seriously,” Ms. Cheney said, “will steer our party and our nation into the future. We will right the unforgivable wrongs of Jan. 6.”