Connecticut Sen. Chris Murphy said Sunday that Ukraine “no doubt” felt pressured to conform to President Donald Trump’s wishes and there is very clear evidence of a quid pro quo arrangement.

The Trump administration has repeatedly dismissed allegations of quid pro quo regarding conversations asking Ukrainian officials, including President Volodymyr Zelensky, to investigate former Vice President Joe Biden and his son Hunter. But officials have been making statements under oath that U.S. military aid was made contingent on Ukraine opening such an investigation.

The senator said he told the Ukrainian president, whom he described as “a total political novice,“ that it wouldn’t be good to get dragged into American politics during a visit in September — and Zelensky agreed. However, Murphy later added, Ukraine cannot survive Russia’s ongoing military assault without American help.

On Sunday, Vice President Mike Pence dodged saying whether he thought officials connecting U.S. aid to the request for a Biden investigation were lying in their testimony.

"I can only tell you what I know," he said on CBS, again denying any quid pro quo.