Rep. Adam Kinzinger (R-IL) speaks after the Republican House caucus voted to remove Rep. Liz Cheney (R-WY) of her leadership, at the U.S. Capitol on on May 12, 2021 in Washington, DC.

House Speaker Nancy Pelosi has added Republican Rep. Adam Kinzinger, an outspoken Trump critic, to the House select committee charged with investigating the Jan. 6 attack, she said in a statement on Sunday.

"I swore an oath to uphold and defend the Constitution — and while this is not the position I expected to be in or sought out, when duty calls, I will always answer," Kinzinger said in a statement announcing he accepted the appointment.