Michael McKinley, right, the top aide to Secretary of State Mike Pompeo, arrives for a joint interview with the House Committee on Foreign Affairs, House Permanent Select Committee on Intelligence, and House Committee on Oversight and Reform on Capitol Hill in Washington, Wednesday, Oct. 16, 2019. (AP Photo/Susan Walsh)

Kurt Volker, President Donald Trump's former special envoy to Ukraine, arrives on Capitol Hill in Washington, Wednesday, Oct. 16, 2019. (AP Photo/Susan Walsh)

Rep. Adam Schiff, D-Calif., Chairman of the House Intelligence Committee, right, accompanied by House Speaker Nancy Pelosi of Calif., left, speaks about the House impeachment inquiry into President Donald Trump at a news conference on Capitol Hill in Washington, Tuesday, Oct. 15, 2019. (AP Photo/Andrew Harnik)

Michael McKinley, a former top aide to Secretary of State Mike Pompeo, right, arrives on Capitol Hill in Washington, Wednesday, Oct. 16, 2019, to testify before congressional lawmakers as part of the House impeachment inquiry into President Donald Trump. (AP Photo/Andrew Harnik)

Deputy Assistant Secretary of State George Kent, second from right, arrives to appear before a joint House Committee on Foreign Affairs, Permanent Select Committee on Intelligence, and Committee on Oversight and Reform for a deposition on Capitol Hill in Washington, Tuesday, Oct. 15, 2019. (AP Photo/Manuel Balce Ceneta)