Sen. Ron Johnson, R-Wis., said Sunday that the Trump administration officials who provided information to the anonymous whistleblower about the president's efforts to pressure Ukraine "exposed things that didn't need to be exposed."

"This would have been far better off if we would've just taken care of this behind the scenes," Johnson said in an interview on NBC News' "Meet the Press." "We have two branches of government. Most people, most people wanted to support Ukraine. We were trying to convince President Trump."

Johnson's comments come days after the first public hearings in the impeachment inquiry. Democrats are seeking to prove that Trump leveraged military assistance and an Oval Office meeting in exchange for investigations into former vice president Joe Biden and a debunked theory concerning purported Ukrainian interference in the 2016 presidential election.

The interview also comes amid intensifying scrutiny of the actions of U.S. Ambassador to the European Union Gordon Sondland, who is among those expected to testify publicly this week.

According to testimony released Saturday, a former White House national security official told House investigators that Sondland was acting at Trump's behest and spoke to a top Ukrainian official about exchanging military aid for political investigations - two elements at the heart of the impeachment inquiry.

Republicans have struggled to defend Trump's actions, and Johnson on Sunday lamented the "damage that's being done to our entire country through this entire impeachment process."

"It's going to be very difficult for future presidents to have a candid conversation with a world leader, because now we've set the precedent of leaking transcripts," he said, referring to the release of rough transcripts of Trump's calls with Ukrainian President Volodymyr Zelensky. "The weakening of executive privilege is not good."

Johnson also argued that the whistleblower's actions ultimately have not helped the U.S.-Ukraine relationship.

"And, by the way, those individuals that leaked this, if their interest was a stronger relationship with the Ukraine, they didn't accomplish this," he said. "Having this all come out into public has weakened that relationship, has exposed things that didn't need to be exposed."

In recent weeks, Johnson has emerged as the member of Congress most closely involved in the Ukraine saga. The Wisconsin Republican met in July with a former Ukrainian diplomat who has circulated unproven claims that Ukrainian officials assisted Hillary Clinton's 2016 presidential campaign.

Johnson and Sen. Chris Murphy, D-Conn., also met with Zelensky in September, at a time when U.S. aid to the country was still being held up.