The U.S. Senate on Saturday voted to acquit former President Donald Trump, concluding his second impeachment trial – the shortest in U.S. history at only five days.

Seven Republican senators joined all the Democrats in the 57-43 vote, failing to reach the two-thirds majority required for convicting Trump on the article of impeachment for inciting insurrection leading to the deadly January 6 Capitol riot.

Trump declared victory after surviving the impeachment trial for a second time.

"Our historic, patriotic and beautiful movement to Make America Great Again has only just begun. In the months ahead I have much to share with you, and I look forward to continuing our incredible journey together to achieve American greatness for all of our people," Trump said in a statement. 

U.S. President Joe Biden issued a statement hours after the Senate failed to muster the two-thirds majority needed to convict his predecessor, saying that "this sad chapter in our history has reminded us that democracy is fragile," adding "it must always be defended."

U.S. House Speaker Nancy Pelosi later denounced the senators who made Trump's acquittal possible as a "cowardly group of Republicans" and blamed Senate Minority Leader Mitch McConnell for not allowing the House to deliver the impeachment charge to the Senate while Trump was still in the White House.

McConnell, who voted to acquit Trump, explained the unexpected turnabout at the end of a five-day impeachment trial, by declaring it unconstitutional to convict Trump of misconduct now that the former president has left office and become a private citizen.

But he sharply criticized the former president on Saturday for inciting the Capitol riot by calling Trump "practically and morally responsible" for it.

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

"There's no question – none – that President Trump is practically and morally responsible for provoking the events of the day. No question about it. The people who stormed this building believed they were acting on the wishes and instructions of their president," the top Senate republican added.

Read more:

Trump on trial: Background, arguments, consequences

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In comments that echoed the prosecution's case, McConnell said Trump had orchestrated "an intensifying crescendo of conspiracy theories" and described the former president as "determined to either overturn the voters' decision or else torch our institutions on the way out."

McConnell suggested that Trump could still face criminal prosecution for his acts. "President Trump is still liable for everything he did while he was in office as an ordinary citizen," McConnell said. "He didn't get away with anything. Yet."

Trump was impeached on January 13 by the Democrat-led House on one article of inciting insurrection leading to the Capitol riot which interrupted Congress' electoral vote count of Biden's victory. 

Five people, including a Capitol police officer, died in the riot.

(With input from Xinhua, Reuters)