Former US vice president Mike Pence said he did not have the power to reverse the outcome of the 2020 presidential election and President Donald Trump was mistaken in believing he did.
Mr Trump, in a bid to stay in office, pressured Mr Pence to block congressional certification of the results while presiding over the proceedings on 6 January 2021.
Mr Pence, a loyal lieutenant during the four years of Mr Trump's tumultuous presidency, opted not to block certification.
The former Apprentice host has often disparaged Mr Pence since then and, last week, issued a fresh statement saying the former vice president could have "overturned" the election.
Former vice president Mike Pence said he understood disappointment about the result. Source: Orlando Sentinel
"President Trump is wrong," Mr Pence said in a speech to the Federalist Society, a conservative legal organisation, in Lake Buena Vista, Florida. "I had no right to overturn the election."
"The presidency belongs to the American people, and the American people alone. And frankly there is no idea more un-American than the notion that any one person could choose the American president," Mr Pence added.
His comments represented his most forceful criticism of Mr Trump to date, and a Trump spokesperson did not immediately respond to a request for comment.
"I understand the disappointment many feel about the last election. I was on the ballot," Mr Pence said.
"Whatever the future holds, I know we did our duty that day. John Quincy Adams reminds us: Duty is ours; results are God's," he added, quoting a 19th century US president.
"And the truth is there's more at stake than our party or political fortunes. Men and women: if we lose faith in the Constitution, we won't just lose elections, we'll lose our country," Mr Pence added.
A mob of supporters of US President Donald Trump fight with members of law enforcement as they storm the US Capitol Building in Washington DC. Source: Reuters
A 'dark day'
While Mr Pence was presiding over the certification, a mob of Trump supporters stormed the Capitol in a failed bid to stop the certification.
Mr Pence and US politicians inside the Capitol fled from the rioters.
In his speech on Friday, Mr Pence called 6 January a "dark day."
His comments stand in contrast to the Republican Party, which on Friday censured Representatives Liz Cheney and Adam Kinzinger for joining a House of Representatives select committee investigating the 6 January attack. The party said the Democrat-led inquiry was persecuting "ordinary citizens engaged in legitimate political discourse".
Republicans aligned with Trump have made the false election claims a key part of their campaigns heading into the November 2022 midterm elections in which the party is seeking to win back control of Congress from the Democrats.
Around 55 per cent of Republicans nationally think the 2020 election was stolen, according to Reuters/Ipsos polls.
Mr Trump, who continues to have a strong grip over the party even out of office for more than a year, has hinted he could run for president again in 2024.
Donald Trump has hinted at another presidential run in 2024. Source: AP
At a rally in Texas on Saturday, he said that if he were to win in 2024, he would pardon people charged with criminal offences in connection with the 6 January riot.
In a speech moments before the attack, Mr Trump repeated his false claims that the election was stolen through widespread voting fraud.
He called upon Mr Pence to "do the right thing" and block certification of the election results, while urging his supporters to go to the Capitol to "stop the steal".
"All Vice President Pence has to do is send it back to the states to recertify and we become president and you are the happiest people," Mr Trump told his supporters during the speech.
Later, some of the rioters at the Capitol chanted "Hang Mike Pence" and some set up a makeshift gallows.
