WASHINGTON -- US President Joe Biden said late Saturday that though most Republican senators voted to acquit former President Donald Trump of inciting insurrection leading to the deadly violence on Capitol on Jan 6, the "substance of the charge" in the impeachment trial was not in dispute.

"While the final vote did not lead to a conviction, the substance of the charge is not in dispute," Biden said in a statement.

"Even those opposed to the conviction, like Senate Minority Leader McConnell, believe Donald Trump was guilty of a 'disgraceful dereliction of duty' and 'practically and morally responsible' for provoking the violence unleashed on the Capitol," Biden said, repeating his calls for unity to "end this uncivil war and heal the very soul of the nation."

Only seven Republican senators joined all the 50 Democrats to vote "guilty," failing to reach two-thirds majority required for the conviction on the article of impeachment.

The 57-43 vote in the currently evenly split Senate yielded the most bipartisan margin in favor of conviction in US history, showing further divide among Republicans in the post-Trump era.

In a speech on the Senate floor shortly after the vote, McConnell said the protesters had been "fed wild falsehoods by the most powerful man on Earth -- because he was angry he'd lost an election," adding that Trump's actions preceding the riot "were a disgraceful dereliction of duty."

However, McConnell insisted that impeaching Trump after he exited office was not the correct mechanism by which to hold him accountable.

"Impeachment was never meant to be the final forum for American justice," McConnell said, noting Trump is "still liable for everything he did."

Trump was impeached on Jan 13 by the Democrat-led House of Representatives in the wake of the Capitol siege which interrupted Congress' electoral vote count of Biden's victory. Five people died in the attack, including a Capitol police officer.

Before the vote on Saturday, more than a third of the upper chamber, all Republicans, had twice voted to rule that the impeachment trial is unconstitutional since Trump now is a private citizen.

Trump is the first ever US president to have been impeached and tried twice. His second impeachment trial lasted just five days, the shortest one in US history.