Lt. Col. Alexander S. Vindman, a National Security Council expert on Ukraine, appeared before the House Intelligence Committee Tuesday morning to deliver a first-hand account of the July call between Donald Trump and Ukraine president Volodymyr Zelensky. In his opening statement, the decorated military official said:

“On July 25, 2019 the call occurred. I listened in on the call… I was concerned by the call. What I heard was inappropriate and I reported my concerns to Mr. Eisenberg. It is improper for the President of the United States to demand a foreign government investigate a U.S. citizen and a political opponent… It was also clear that if Ukraine pursued aninvestigation into the 2016 elections, the Bidens and Burisma, it would be interpreted as a partisan play. This would undoubtedly result in Ukraine losing bipartisan support, undermining U.S. national security and advancing Russia’s strategic objectives in the region. I want to emphasize to the committee that when I reported my concerns on July 10th relating to Ambassador Sundaland, and then July 25th relating to the president, I did so out of a sense of duty.”

Vindman also defended his colleagues from the smear attacks that Trump and others have levied at others who have testified.

Vindman, who was born in the Soviet Union, closed out his statement by directing this powerful remark to his father.

Watch his full opening statement above.

Jennifer Williams, a national security aide for Vice President Mike Pence also testified Tuesday morning. Her account of the July 25th call was also firsthand. She said the call was “unusual” and brought it to Pence’s attention.

Both Williams and Vindman said they heard the word Burisma on the July 25th call, something that wasn’t mentioned in the transcript of the call that the White House released.

There was one question Williams would not answer. When asked about a September 18th call between Pence and Zelensky, she referred to her attorney who said the White House has blocked Williams from talking about that conversation publicly. She did say she would offer a classified statement in writing to the committee.