WASHINGTON—A senior State Department official went before House impeachment investigators Saturday and said that top officials stymied a show of solidarity for the former U.S. ambassador to Ukraine after President Trump had her removed, according to a person familiar with his closed-door testimony.

Philip Reeker, the acting assistant secretary of state in the Bureau of European and Eurasian Affairs, was also present for a White House interagency meeting during which a Department of Defense official raised concerns about a decision by the White House to hold military aid to Ukraine, the person familiar with the testimony said.

The House Intelligence Committee subpoenaed Mr. Reeker’s testimony after the State Department directed him not to appear for his scheduled Saturday deposition, according to an official working on the impeachment inquiry. The official said the State Department was also attempting to limit any testimony that did occur, and that Mr. Reeker was complying with the subpoena and answering questions.

Mr. Reeker was named to the job in March, around the time Mr. Trump ordered the removal of Marie Yovanovitch, the U.S. ambassador to Ukraine. Mr. Trump’s personal lawyer Rudy Giuliani and others had accused Ms. Yovanovitch of undermining the president abroad and of obstructing efforts to persuade Kyiv to investigate former Vice President Joe Biden.

Ms. Yovanovitch “was a primary concern from his first week on the job,” the person familiar said, relaying Mr. Reeker’s position on the issue.