KIEV (Reuters) - A group of three U.S. Senators visited Kiev on Friday to convey a message of continued bipartisan support for Ukraine after it got entangled last year in President Donald Trump’s impeachment trial.

The United States has been the most powerful backer of Ukraine in its standoff with Russia over Moscow’s 2014 annexation of Crimea and support for separatist fighters in a simmering conflict in the eastern Donbass region.

But their relationship was tested after Trump froze nearly $400 million in security aid and pressed Ukrainian President Volodymyr Zelenskiy to investigate one of the Republican president’s Democratic rivals, former vice president Joe Biden.

Trump was impeached by the Democratic-led House of Representatives but was acquitted this month in the Republican-led Senate.

“I think we all are confident that President Zelenskiy does not want to be involved in U.S. politics, and we hope that any pressure (that) existed in the past to do so is over,” Democratic Senator Chris Murphy said after meeting the Ukrainian leader..

“Our message is we want to put this impeachment question behind us, and we want to be moving together, Republicans and Democrats, in supporting Ukraine.”

Murphy was accompanied to Kiev by Republican Senators Ron Johnson and John Barrasso.

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In a statement, posted on his office’s website, Zelenskiy said he wanted to change Ukraine’s global image so that people did not associate the country with corruption.

At the heart of the impeachment case was a transcript of a July 25 telephone call in which Trump asked Zelenskiy to work with U.S. Attorney General William Barr and Trump’s personal attorney, Rudy Giuliani, to investigate Biden.

The fallout from the impeachment trial continued in Washington this week, as Trump said the military may consider disciplining former National Security Council aide Alexander Vindman, who testified in the case.

Asked if he regretted sending Giuliani to Ukraine last year, Trump said on Thursday in a radio interview: “No, not at all.” He also defended engaging Giuliani, a former New York mayor.

“Rudy is a high-quality guy,” he said in an interview that aired on iHeart Radio.

Trump also said he may stop allowing government aides to listen in on his telephone calls with foreign leaders.

Barr this week acknowledged that the U.S. Department of Justice was accepting and reviewing information from Giuliani ahead of the 2020 U.S. presidential election, sparking concern from Democrats and some legal experts.