Manuel Balce Ceneta/AP; Patrick Semansky/AP A composite image of Col. Alexander Vindman and President Donald Trump.

Col. Alexander Vindman, a top White House National Security Council aide, testified last week that the White House left out some phrases from its memo summarizing President Donald Trump’s Ukraine call.

Trump has claimed Vindman is a “Never Trumper,” a member of a Republican movement that tried to stop Trump from becoming president in 2016.

There is no evidence to suggest this. Asked about it on Sunday, Trump said he would release evidence “real soon.”

Vindman is a particularly damaging witness in Trump’s impeachment inquiry because of his firsthand knowledge of the call that sparked House Democrats’ impeachment inquiry.

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US President Donald Trump has threatened to release damaging intelligence against the White House national security aide who testified that the White House omitted some phrases from its summary of the phone call that sparked Democrats’ impeachment inquiry.

Lt. Col. Alexander Vindman, a Purple Heart recipient who is a top official on the White House National Security Council, testified last Tuesday that the White House left out some information from its memo summarizing Trump’s July 25 call with Ukrainian President Volodymyr Zelensky.

Examples included direct mentions by Zelensky of Burisma, the Ukrainian gas company where former Vice President Joe Biden’s son Hunter worked, and by Trump of the elder Biden discussing Ukraine corruption.

Hours after news outlets reported on Vindman’s testimony,Trump claimed that the White House aide was a “Never Trumper,” or a member of the Republican movement that opposed Trump’s candidacy in 2016.

Associated Press Vindman leaving a closed-door meeting on Capitol Hill on Tuesday after testifying as part of the House impeachment inquiry.

There is no evidence that Vindman was part of this group. But when reporters asked about it Sunday, Trump threatened to release information “real soon.”

Here’s how the exchange went down, as can be seen in the video below:

Reporter: Sir, what evidence do you have that Col. Vindman is a Never Trumper?

Trump: We’ll be showing that to you real soon, OK?

The president then ignored a follow-up request to describe the information he claimed to have.

NEW: President Trump threatens to expose information about Lt. Col. Vindman. Watch. pic.twitter.com/pEmUlJkqvB — Kelly O'Donnell (@KellyO) November 3, 2019

Vindman, who listened to the Ukraine call as it happened, had said last week that he tried to add Zelensky’s mention of Burisma and Trump’s discussion of Biden into the rough White House transcript but was not able to do so and was not sure why.

He is a particularly damaging witness in Trump’s impeachment inquiry because of his firsthand knowledge of the call.

His testimony also undercuts that of Gordon Sondland, the US ambassador to the European Union, who Vindman said made “inappropriate” statements underscoring the importance of Ukraine giving Trump politically motivated investigations the president wanted.

Some Trump supporters and conservative commentators have accused Vindman – who was born in Ukraine but moved to the US when he was 3 – of being a spy for Ukraine. They have been met with harsh criticism on both sides.

Biden defended Vindman and called attacks on his character and loyalty “despicable.” Rep. Liz Cheney, a Republican from Wyoming, also said it was “shameful” to question the patriotism of officials like Vindman.

Gen. Peter Zwack, who was Vindman’s boss in Moscow, also told PRI’s The World: “I find preposterous the innuendo that he somehow is a double agent. That was just fear and hate-mongering and I found it reprehensible.”

The House last week passed a resolution to formalise the impeachment inquiry. Trump has repeatedly called it a “witch hunt.” An Insider poll has also found about half of Americans supported impeaching Trump.

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