"The secretary did not speak to the president this morning and is unaware of the reason, but he is grateful for the opportunity to serve, and still believes strongly that public service is a noble calling and not to be regretted," Undersecretary of State Steve Goldstein said.
Tillerson arrived back in Washington before dawn on Tuesday after a tour of African countries and a few hours later Trump announced abruptly on Twitter that he was to be replaced by CIA director Mike Pompeo.
"We wish Secretary-Designate Pompeo well," Goldstein -- who is undersecretary of state for public affairs and public diplomacy -- said, in a series of tweets from his official account.
"The secretary will miss his colleagues at the Department of State and enjoyed working together with the Department of Defense in an uncommonly robust relationship," he added, in a nod to Tillerson's close working relationship with Secretary of Defense Jim Mattis.
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