President Biden is striking back against Republicans who claim he was not the one who issued a series of high-profile clemency decisions toward the end of his term, insisting he used an autopen to sign off on the series of presidential pardons.

In a rare interview published on Sunday evening, Mr. Biden said he made “every decision” on the scores of clemencies and that the autopen device was used due to the sheer number. He called President Trump and others in the Republican Party “liars” for making claims that his aides had carried out the pardons on his behalf.

“I made every single one of those [clemency] decisions,” he said in a phone interview with the New York Times. “I understand why Trump would think that, because obviously, I guess, he doesn’t focus much. Anyway, so — yes, I made every decision.”

Mr. Biden had reduced the sentences of nearly 4,000 federal convicts. He also preemptively pardoned people close to his administration who he believed may have been potential criminal investigation targets of a vengeful Mr. Trump, including his own family.

“The autopen is, you know, is legal. As you know, other presidents used it, including Trump,” he said. “But the point is that, you know, we’re talking about a whole lot of people.” 

The Times also obtained email messages that show Mr. Biden meeting with aides on January 19, the last full day of his term. While he admitted that he did not approve every individual categorical clemency, he did hold extensive discussions regarding the pardons.

In an email message to a larger group of aides, Chief of Staff Jeff Zients wrote, “I approve the use of the autopen for the execution of all of the following pardons.”

The interview was the first since a series of concurrent investigations launched by the Trump administration, the Department of Justice, and Congress on the clemency decisions made by Mr. Biden, as well as his cognitive abilities throughout his time as president.

“Everybody knows how vindictive he is, so we knew that they’d do what they’re doing now,” Mr. Biden said of Mr. Trump. 

“I consciously made all those decisions.”