Lt. Col. Alexander Vindman, a Ukraine expert on the White House National Security Council, told congressional investigators on Tuesday that he suggested edits to the White House summary of a July 25 call between President Donald Trump and the president of Ukraine, The New York Times reports.

Vindman reportedly said some of his edits seemed to make it in but others adding a direct mention of Burisma by Ukrainian President Volodymyr Zelensky and a mention by Trump of recordings of Biden discussing Ukraine corruption did not.

The Times said White House summaries of the kind documenting the July 25 call were made using note-takers as well as voice-recognition software "to create a rough transcript that is a close approximation of the call." It added that the apparently missing details did "not fundamentally change lawmakers' understanding of the call."

The rough transcript of the call was given to Vindman to offer edits, The Times reported, as he was among officials who had listened in on the conversation.

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A top national security aide is said to have told House impeachment investigators Tuesday that the White House summary of President Donald Trump's July 25 call to Ukraine was missing phrases including a mention by name of Burisma, the energy company on whose board former Vice President Joe Biden's son Hunter Biden served.

The New York Times reported Tuesday that Lt. Col. Alexander Vindman, a Ukraine expert on the White House National Security Council, told congressional investigators that he tried to edit the summary to add the details from the call, which he listened in on.

He said that he seemed to be successful in adding some details, according to The Times, citing three unnamed sources, but that some additions were left out. Among them were what he recalled as a mention of the gas company Burisma by name by Ukrainian President Volodymyr Zelensky and a mention by Trump of recordings of former Vice President Joe Biden discussing Ukraine corruption. It is unclear why some edits seemed to make it into the summary while others did not.

The Times said that the missing phrases did "not fundamentally change lawmakers' understanding of the call" but that the testimony did appear to fill in some holes in the transcript.

Though the summary did not include the direct mention of Burisma, for example, The Times noted that it still contained a reference to "the company" and that such summaries relied on note-takers and voice-recognition software that sometimes misses proper nouns like company names.

The Times suggested Vindman's testimony cleared the fog surrounding some of the ellipses that appeared on Trump's side of the conversation. In one of the instances, Vindman reportedly told investigators, the president mentioned tapes of Biden talking about Ukraine corruption. It was most likely a reference to a 2018 video of the former vice president talking about pressuring the country into ousting its top prosecutor Viktor Shokin, leveraging a billion dollars in loan guarantees, The Times reported. At the time, multiple Western governments were pushing to have Shokin removed over concerns that he wasn't pursuing corruption cases among Ukrainian politicians.

Earlier this month, the diplomat George Kent told congressional investigators that Trump's personal lawyer Rudy Giuliani pushed the State Department to grant Shokin a visa to the US after the Ukrainian prosecutor promised info on Democrats.

Vindman is the first White House official who listened in on the July 25 call to testify in the impeachment inquiry, given the White House has been steadfast in its refusal to comply with subpoenas. In his opening statement, acquired by multiple news outlets on Monday, Vindman said he felt "a sense of duty" and had feared Trump's actions would "undermine US national security."

"I am a patriot, and it is my sacred duty and honor to advance and defend our country irrespective of party or politics," he said in the opening statement.

The call was the subject of a whistleblower complaint filed by an intelligence official in August that became the impetus for Democrats' impeachment inquiry. The House is set to vote on the inquiry's procedures on Thursday.

The rough transcript of the call was given to Vindman, The Times reported. He offered edits, as an official who listened in on the conversation, and gave his edits to his boss on the National Security Council.

Following the call he also flagged the conversation as concerning, The Times said, and sought out the National Security Council's legal adviser, John Eisenberg — one of multiple times he said he raised the issue with his superiors. It was Eisenberg who moved the transcript to a secure server that had limited access, according to The Times. Its placement in the secure server could have been why the edits were not made.