— Tuesday, Nov. 19, morning: Jennifer Williams, an aide to Vice President Mike Pence; Lt. Col. Alexander Vindman, Director for European Affairs at the National Security Council.
— Tuesday, Nov. 19, afternoon: Ambassador Kurt Volker, the former U.S. special envoy to Ukraine; Tim Morrison, a White House aide with the National Security Council.
— Wednesday, Nov. 20, morning: Ambassador Gordon Sondland, U.S. Ambassador to the European Union.
— Wednesday, Nov. 20, afternoon: Laura Cooper, Deputy Assistant Secretary of Defense for Russian, Ukrainian, and Eurasian Affairs; David Hale, Under Secretary of State for Political Affairs.
— Thursday, Nov. 21, morning: Fiona Hill, former National Security Council senior director for Europe and Russia.