House magistrate president Jerry Nadler said he was "prepared" if Senate Republicans tried to call Hunter Biden as a witness during the impeachment process.
He added that he doesn't see Biden as a relevant witness.
"Let me say, we are prepared, but the relevant question is relevance. It is relevance. In any trial, you call witnesses who have information on the charges, the charges."
Nadler said Biden has "no information" and is not "a relevant witness".
"Any trial judge in this country will judge that witness irrelevant and inadmissible," he added.
More information on this: Hunter Biden's position on the board of the Ukrainian energy company Burisma was at the center of the debate during the impeachment investigation. Neither Hunter Biden nor his father, former Vice President Joe Biden, were found to have committed an offense.