Hasn't named one yet.
-- Where's a list of pending? --
Pending in committee
Pending on Executive Calendar
Confirmed
U.S. Senate: Nominations has those links, and more, e.g., SCOTUS, Courts, Cabinet.
The White House Nominations & Appointments pages has similar info, not as concise.
See too, US State Department Lists of Ambaassaors, in particular Ambassador Assignments Overseas May 10, 2017 (UK position is VACANT)
You are the best! Thanks much!!