Feb. 19 (UPI) -- John Rood, the Defense Department undersecretary for policy who warned against withholding military aid to Ukraine, announced his resignation Wednesday.
"It's my understanding from [Defense Secretary Mark] Esper that you requested my resignation," Rood wrote. "Senior administration officials appointed by the President serve at the pleasure of the President, and therefore, as you have requested, I am providing my resignation effective February 28, 2020."
Trump sent a tweet of thanks to Rood on Wednesday.
Rood informed the U.S. Congress in May 2019 that Ukraine had made adequate progress in combating corruption to receive a promised $250 million in military assistance. The aid was a key issue in Trump's impeachment, which alleged the president held up military assistance to Ukraine as leverage to persuade Ukrainian President Volodymyr Zelensky to announce investigations of Democratic presidential candidate Joe Biden and son Hunter Biden.
Trump was acquitted in the Senate and fired Lt. Col. Alexander Vindman, the Ukraine expert at the National Security Council, and Gordon Sondland, U.S. ambassador to the European Union, who testified in the House of Representatives' impeachment hearings.
As undersecretary, Rood led a long-delayed Pentagon outline for future U.S. missile defense plans and changed its policy regarding the Chinese telecommunications company Huawei by overruling researchers who said restricting exports to the company could slow the United States' competitive edge.
Rood follows several top-ranking officials in leaving the Defense Department in recent months, largely through Trump's orders. They include Secretary of Defense chief of staff Eric Chewning, Assistant Secretary of Defense Randall Schriver, Principal Deputy Under Secretary of Defense for Intelligence Kari Bingen, Defense Advanced Research Projects Agency Director Steven Walker, Navy Secretary Richard Spencer, Deputy Assistant Secretary of Defense Middle East Mick Mulroy, and Acting Assistant Defense Secretary Mark Mitchell.
James Anderson, currently performing the duties of the Defense Department's undersecretary for policy, will fill in for Rood until a permanent replacement is appointed, the White House announced.