Steve Ricchetti, who was a top adviser to former President Joe Biden and considered to be in his inner circle, said that Biden was “fully capable of exercising his presidential duties” in a voluntary interview with the House Oversight and Accountability Committee on Wednesday, according to a prepared introductory statement obtained by The Hill.

“Let me be clear: At all times during his presidency, I believed that President Biden was fully capable of exercising his Presidential duties and responsibilities, and that he did so,” Ricchetti’s prepared statement said. “Neither I, nor anyone else, usurped President Biden’s constitutional duties, which he faithfully and fully carried out each and every day.”

Ricchetti appeared for a transcribed interview with the House Oversight and Accountability Committee for the Republican-led panel’s investigation into Biden’s mental acuity and use of an autopen.

Ricchetti said there was “certainly no conspiracy to hide the President’s mental condition from the American people,” and that he was “not aware of any effort by any member of the White House staff to usurp the President’s authority to make decisions or to sign important documents without his knowledge.”

“Did he stumble? Occasionally. Make mistakes? Get up on the wrong side of the bed? He did – we all did. But I always believed – every day – that he had the capability, character, and judgment to be President of the United States,” Ricchetti said.

Ricchetti appeared voluntarily before the hours-long voluntary interview that started at 10 a.m. on Capitol Hill on Wednesday. He did not answer questions from reporters while heading into the interview.

His statement said efforts by Republicans and the Trump administration “to taint President Biden’s legacy with baseless assertions about President Biden’s mental health are an obvious attempt to deflect from the chaos of this Administration’s first six months.”

Ricchetti charged that the House Oversight Committee’s investigation “is part of a concerted effort by the Administration and its Congressional allies to diminish the record of the former President by advancing the false narrative that President Biden was mentally unable to perform his Constitutional duties and that members of his staff usurped the President’s Article II powers.”

The top Biden aide said he appeared voluntarily because he believed it important to “forcefully rebut this false narrative about the Biden Presidency and our role in it.”

Several other former aides from the Biden administration that the panel has sought testimony from did not appear voluntarily and were subpoenaed by House Oversight Committee Chair James Comer (R-Ky.).

These Biden aides invoked their Fifth Amendment rights and refused to answer the committee’s questions in recent depositions: Anthony Bernal, former chief of staff to first lady Jill Biden; deputy director of Oval Office operations Annie Tomasini; and Biden’s former White House doctor Kevin O’Connor.

Others, though, have appeared voluntarily and answered the panel’s questions, including former White House chief of staff Ron Klain and former Biden aides Ashley Williams and Neera Tanden.

Mike Donilon, another top Biden aide who was a senior advisor to the President, is scheduled to appear for a voluntary interview on Thursday.

Other Biden aides scheduled for voluntary transcribed interviews through September include Bruce Reed, former deputy chief of staff for policy; Anita Dunn, former senior advisor to the president for communications, Ian Sams, former special assistant to the president and senior advisor in the White House Counsel’s Office; Andrew Bates, a Biden senior deputy press secretary; Karine Jean-Pierre, former White House press Secretary; and Jeff Zients, former White House chief of staff.

NewsNation contributed to this report.