Washington — Michael McKinley, a former top adviser to Secretary of State Mike Pompeo, told the House committees leading the impeachment probe that he resigned his post after a "puzzling and baffling" lack of support for the former U.S. ambassador to Ukraine, according to a transcript of his testimony released Monday.

In his appearance before the committees October 16, 2019, McKinley told lawmakers he resigned after 37 years in foreign service over the State Department's treatment of Marie Yovanovitch, the former U.S. ambassador to Ukraine who was recalled from her post earlier this year, and other diplomats. He testified about his failed attempts to urge Secretary of State Mike Pompeo to release a strong statement of support for the former ambassador in response to President Trump's disparaging remarks about her.

According to the summary of Mr. Trump's July 25 call with Ukrainian President Volodymyr Zelensky, Mr. Trump said of Yovanovitch, "The former ambassador from the United States, the woman was bad news and the people she was dealing with in the Ukraine were bad news so I just want to let you know that," according to the White House summary. The president told Zelensky the ambassador was "going to go through some things."

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Download the full text of McKinley's testimony here

After the summary became public on September 25, McKinley said he was troubled by Mr. Trump's comments "impugning" Yovanovitch, who he called "a serious, committed colleague." He said the president's comments "raised alarm bells for me."

McKinley told lawmakers the call summary clarified a couple of things for him. He said that "State Department officials, if not the State Department itself, were being drawn into the domestic political arena in some way." And he also told the committees it was clear that both special envoy Kurt Volker and U.S. Ambassador to the European Union Gordon Sondland "were engaging the Ukrainian Government in conjunction with Rudy Giuliani on domestic political issues."

Michael McKinley arrives on Capitol Hill for a closed-door hearing at the Capitol on October 16, 2019, in Washington, D.C. Getty

After he learned what Mr. Trump had said on the call, McKinley said he spoke with Pompeo and other top State Department officials about releasing a statement of support for Yovanovitch. Pompeo did not comment, according to McKinley. All but one of the other officials agreed with McKinley's recommendation.

In a meeting several days later, McKinley said he told colleagues the lack of support for Yovanovitch was "having a dramatic impact on the morale of the building," calling it "puzzling and baffling."

Pompeo decided against issuing a statement. Soon afterward, McKinley tendered his resignation over what he said appeared to be "the utilization of our ambassadors overseas to advance domestic political objectives."

He told the secretary of state he was resigning in part because of the "lack of public support for Department employees." Pompeo "did not respond at all" to his concerns, McKinley told the committees.

On October 20, Pompeo appeared on ABC News' "This Week with George Stephanopoulos," where he was asked about McKinley's assertion that he had been asked for a statement of support for Yovanovitch.

"From the time that Ambassador Yovanovitch departed Ukraine until the time that [McKinley] came to tell me that he was departing, I never heard him say a single thing about his concerns with respect to the decision that was made," Pompeo said. "Not once — not once, George — did Ambassador McKinley say something to me during that entire time period."