KYIV, Ukraine (AP) - U.S. Secretary of State Mike Pompeo opened a visit to Ukraine on Friday facing a delicate balancing act as he tries to boost ties with a critical ally at the heart of the impeachment trial while not providing fodder for Democrats seeking to oust President Donald ...

During a private event Thursday in Austin, Texas, former National Security Adviser John Bolton praised five government officials who testified in the House impeachment inquiry, KXAN reports.During a question-and-answer session, Bolton said Fiona Hill, Tim Morrison, Lt. Col. Alexander Vindman, Bill Taylor, and former U.S. Ambassador to Ukraine Marie Yovanovitch all "acted in the best interest of the country as they saw it and consistent to what they thought our policies are." He also said 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."In her testimony, Hill, President Trump's former top Russia adviser, debunked a conspiracy theory that it was Ukraine, not Russia, that meddled in the 2016 presidential election. Morrison, a former senior White House national security official, testified that U.S. Ambassador to the E.U. Gordon Sondland told him he let Ukraine know Trump would unfreeze military aid once leaders announced investigations into Democrats.Taylor, the former acting U.S. ambassador to Ukraine, also testified that he was told aid to Ukraine was dependent on investigations into former Vice President Joe Biden. Vindman, the director of European Affairs for the White House National Security Council, was on Trump's July 25 phone call with Ukrainian President Volodymyr Zelensky, and reported to his superiors that Trump requested Zelensky open an investigation into Biden. Yovanovitch testified that she was the victim of a successful smear campaign orchestrated by Trump's personal attorney, Rudy Giuliani.On Sunday, The New York Times reported that in his upcoming book, Bolton contradicts Trump's claims that there was no quid pro quo with Ukraine. Democrats want Bolton to testify during Trump's impeachment trial, and the Senate is expected to vote on calling more witnesses Friday.More stories from theweek.com Mitch McConnell's rare blunder John Bolton just vindicated Nancy Pelosi 7 witheringly funny cartoons about the GOP's John Bolton problem

The motion to call witnesses requires a simple majority in the GOP-controlled Senate, requiring at least four Republican senators to vote yes.

Republicans prepared to defend their expected acquittal of President Donald Trump, on Sunday's TV talk shows, after their Senate votes to reject witness testimony at his impeachment trial sparked criticism they were aiding a cover-up and abdicating their duties. Criticism only intensified late Saturday after US media reported that US officials cited presidential privilege in redacting 24 emails related to Trump's hold on military assistance to Ukraine, an issue at the heart of his impeachment trial for abuse of power and obstruction of Congress. Trump on Saturday claimed his polling numbers were up after the Senate paved the way for his acquittal next Wednesday.

After GOP Sens. Lamar Alexander said he does not want witnesses at the Trump Senate impeachment trial, attention turned Friday to Sen. Lisa Murkowski.