The House has released the testimony of Lieutenant Colonel Alexander Vindman, a National Security Council official who testified before the committees conducting the impeachment inquiry on October 29. Vindman participated in the now-infamous call on July 25 during which President Trump asked the Ukrainian president to investigate a political rival.

From the outset, in his opening statement, Vindman told the committees he "did not think it was proper" for the president to insist that Ukrainian President Volodymyr Zelensky open investigations into Joe Biden and his son, Hunter Biden, as well as Burisma, the energy company that employed Hunter Biden. He said he reported his concerns to the lead counsel at the NSC.

"I realized that if Ukraine pursued an investigation into the Bidens and Burisma, it would likely be interpreted as a partisan play which would undoubtedly result in Ukraine losing the bipartisan support it has thus far maintained," Vindman said. "This would all undermine U.S. national security."

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Read the full transcript here.

During his testimony, Vindman, who is the top Ukraine expert on the National Security Council, told lawmakers that Ukraine had taken "major steps" toward the West and that the election of Zelensky, an outsider who had run on an anti-corruption platform, was a positive development.

In July, Vindman attended a meeting with Ukrainian officials and national security adviser John Bolton, special envoy Kurt Volker, Ambassador to the E.U. Gordon Sondland, and Energy Secretary Rick Perry. Vindman said the discussion was going well until the Ukrainians brought up the idea of a meeting between Zelensky and President Trump.

He said when Sondland "started to speak about Ukraine delivering specific investigations in order to secure the meeting with the president, Ambassador Bolton cut the meeting short." Afterward, Vindman told Sondland his remarks were "inappropriate" and "the request to investigate the Bidens and his son had nothing to do with national security and that such investigations were not something that the NSC was going to get involved in or push." His boss, Fiona Hill, the NSC director for Russia and European Affairs, also told Sondland his statements were inappropriate, Vindman said.

Vindman told lawmakers that he raised concerns about the July 25 call "pretty early on in the call." As Mr Trump mentioned how much the U.S. had done for Ukraine and claimed that Europe had done little, he noted "this was not in the preparation material that I had offered."

He also said that Mr. Trump's remarks were "straying into the territory" of an "unproductive narrative."

Soon after the call, Vindman met with White House attorneys, as well as his twin brother Yevgeny, who also works for the National Security Council, and he "shared" his concerns about the call. But while he found it "troubling and disturbing," and "wrong," Vindman also said "I couldn't say whether it was illegal."

Edits to the July 25 call transcript regarding Biden and Burisma

Vindman said in his testimony that the memorandum summarizing the July 25 call omitted a few elements from the conversation. He said that Mr. Trump commented during the call that there were "recordings" of misdeeds by former Vice President Joe Biden. According to Vindman's recollections and his contemporaneous notes of the call, Mr. Trump's comments that "there are recordings" were replaced in the call summary by ellipses.

In this portion of the call, Mr. Trump said, "Biden went around bragging that he stopped the prosecution, so if you can look into it." This is followed in the call summary by ellipses, but Vindman was saying that the next words were "There are recordings."

Vindman also said that Zelensky specifically referred to Burisma in the call, but the call summary replaced that with "the company."

He told lawmakers that the details about the edits are not just the way he remembers them. "This is what's in my notes," he said. These notes are "in my highly classified notebook," Vindman said.

Hold on security assistance

Vindman said that the Ukrainians first became aware of the pause in U.S. military aid in "mid-August," so the issue being discussed in the July 25 call was not the assistance, but rather, a White House meeting. There was an understanding, Vindman said, that Zelensky could be "strengthened" in his efforts to bring about reform in his country if he had some engagement with Mr. Trump.

Once the news broke of the suspension of the funding, the Ukrainians started asking Vindman about it.

"They ask me, is this true, what we need to do, type of thing. So my impression was they were under pressure," Vindman said, according to the transcript. He responded to them that there was an "ongoing review" and there was still time to reinstate the funding. But he never did learn why the president did not sign off on releasing the funds.

U.S.-Ukraine relationship

Vindman told the committees, "I think as this process wears on, I think the relationship will continue to be damaged and undercut. It undercuts U.S. resolve to support Ukraine and certainly puts a question into their mind whether they, in fact, have U.S. support…it's a trust issue."

Rob Legare and Alan He contributed to this report.