According to state.gov, Lisa Kenna is a career member of the Senior Foreign Service. She is currently the Executive Secretary in the Office of the Secretary, a position she has held since June 2017 (under Rex Tillerson). Previously, she served as the Executive Assistant to the Secretary. She has served overseas in Amman, Cairo, and Peshawar. Domestically, she has worked in the Office of the Secretary, the National Security Council, and at the Department of Defense.
The Executive Secretariat, comprised of the Executive Secretary, five Deputy Executive Secretaries, and their staff, is responsible for coordination of the work of the Department internally, serving as the liaison between the Department’s bureaus and the offices of the Secretary, Deputy Secretary, and Under Secretaries. The Executive Secretariat also handles the Department’s relations with the White House, National Security Council, and other Cabinet agencies.
“S” is in reference to the Secretary of State.
Ambassador Bill Taylor was previously the U.S. Ambassador to Ukraine from June 21, 2006 – May 23, 2009, spanning the G.W. Bush and Obama Administrations.
For Kurt Volker, see Trump’s Special Representative For Ukraine Negotiations Kurt Volker Steps Down
For Gordon Sondland, see here and Oregon Public Broadcasting: Portland Businessman Will Cooperate With US House Impeachment Inquiry; The Intercept: Portland Executive Covertly Donates $1 Million to Inauguration After Being Shamed Over Trump Support.
What role did Sec. Pompeo play?
After defending Trump and denying quid pro quo, Sondland tells career diplomat Bill Taylor, "If you still have concerns, I recommend you give Lisa Kenna or S a call to discuss them directly."
S, being the Secretaryhttps://t.co/lavosjigqc
— Conor Finnegan (@cjf39) October 3, 2019
USEmb Kyiv's Chargé d’Affaires, a.i. William B. Taylor. A career diplomat, he is a West Point and Harvard graduate; Served as infantry platoon leader & combat company commander in the U.S. Army in Vietnam and Germany.https://t.co/vCxMdW9U2M
— Diplopundit (@Diplopundit) October 4, 2019