WASHINGTON () Ron Klain, who served as former President Joe Biden’s first chief of staff, entered the House Oversight Committee’s hearing room just before 10 a.m. Thursday for testimony as part of House Republicans’ probe into Biden’s age and alleged cognitive decline.

Klain took no questions as he entered the room.

House Oversight Committee Chair James Comer, R-Ky., said that Klain was “fairly responsive” to the panel’s questions as the interview broke for a lunch break, expecting to continue questioning into late afternoon.

“I found Mr. Klain to be very credible. He answered every single question. He was fully cooperative,” Rep. Ro Khanna, D-Calif., a member of the committee, said of Klain’s interview.

Khanna added that Klain was “forthcoming” about private conversations he had with Biden and did not avoid questions.

Rep. Andy Biggs, R-Ariz., another member of the committee, said that Klain was “not trying to avoid answering the questions” and was “answering the questions carefully.”

“I think he is telling what he knows accurately,” Biggs said. “He’s trying to be accurate.”

Several other former aides from the Biden administration 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.

affiliate The Hill and The Associated Press contributed to this report.