House Speaker Nancy Pelosi (D-CA) on Saturday blasted Senate Republicans as cowards after the Senate acquitted former US President Donald Trump in the impeachment trial.

"What we saw in that Senate today was a cowardly group of Republicans," Pelosi said of the majority of the Senate Republicans who found Trump "not guilty" of incitement of insurrection, according to Fox News.

The Senate had earlier acquitted Trump again in his second impeachment trial. While the vote was 57-43 in favor of conviction, it was 10 shy of the supermajority needed.

"Justice wasn't done," Pelosi said of the vote, and took aim at Republican Leader Mitch McConnell for delaying the start of the impeachment trial and then saying Saturday he couldn't vote to convict Trump because the trial started after Trump left office.

"You chose not to receive it," Pelosi said of the article of impeachment the House wanted to deliver earlier. "That was the excuse that he used.”

Pelosi also ruled out the idea of now voting to censure Trump, a lesser punishment that some senators had floated as an alternative to impeachment.

"Censure is the slap in the face of the constitution. It lets everybody off the hook,” she said.

"All these cowardly senators who couldn't face up to what the President did and what was at stake for our country are now going to have a chance to give a little slap on the wrist?” continued Pelosi.

"We censure people for using stationary for the wrong purpose. We don't censure people for inciting insurrection that kills people in the Capitol," she added.