AUSTIN (KXAN) — Speaking at a private event in Austin Thursday, Former National Security Advisor John Bolton defended government officials who testified in front of Congress for the U.S. House impeachment inquiry.

The United States Senate could soon decide whether to call Bolton to testify himself in the President’s impeachment trial.

Sources inside the private event tell KXAN Bolton defended former diplomatic and state department officials Fiona Hill, Tim Morrison, Alex Vindman, Bill Taylor, and Marie Yovanovitch.

“All of them acted in the best interest of the country as they saw it and consistent to what they thought our policies were,” said Bolton, during the question-and-answer time after his keynote speech.

He went on to say members of the Trump Administration should “feel they’re able to speak their minds without retribution.”

“The idea that somehow testifying to what you think is true is destructive to the system of government we have — I think, is very nearly the reverse — the exact reverse of the truth,” said Bolton.

The audience applauded after his answer.

Bolton was in Austin at the invitation of Luther King Capitol Management, a Texas company that provides “investment management services to high net worth individuals,” according to its website.

Bolton was the keynote speaker for a private client luncheon Thursday morning at the Hyatt Regency on Barton Springs Road. The program was titled “Foreign Challenges Facing the Trump Administration.”

Bolton briefly mentioned his new book, “The Room Where It Happened: A White House Memoir,” which reportedly supports accusations President Trump tied foreign aid to Ukraine for an investigation into the family of his political rival, Joe Biden. This week, the Trump Administration issued a letter to Bolton to keep him from publishing his new book, claiming it includes classified information.

Democratic Senators have called on Senate Majority Leader Mitch McConnell to support calling Bolton to testify. Bolton said he would testify if subpoenaed.