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’s “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.

Trump on Sunday continued to take aim at his own administration officials, accusing Jennifer Williams, Vice President Pence’s special adviser on Europe and Russia, of being a “Never Trumper.”

“Tell Jennifer Williams, whoever that is, to read BOTH transcripts of the presidential calls, & see the just released ststement from Ukraine,” Trump said in a tweet. “Then she should meet with the other Never Trumpers, who I don’t know & mostly never even heard of, & work out a better presidential attack!”

A Pence spokeswoman did not immediately respond to a request for comment.

Williams is expected to testify publicly on Tuesday.

Her closed-door testimony, which was released Saturday, suggests that the Office of Management and Budget had clamped down on Ukraine aid more than two weeks earlier than has been previously reported.

Both Williams and National Security Council Ukraine expert Lt. Col. Alexander Vindman testified that they noticed as early as July 3 that the military aid for Ukraine that is traditionally controlled by the State Department had been held up, though they were not aware of the reason.

The earlier timeline raises new questions about when the White House may have decided to attempt leveraging Ukraine aid to pressure that country’s leaders to commit to investigations that could politically benefit Trump.

The comments by Trump and Johnson also come 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.

Sen. Chris Murphy (D-Conn.) said he believes Sondland will face pressure this week when he’s asked about inconsistencies between his testimony and that of other recent witnesses in the impeachment inquiry.

“His story continues to change,” Murphy said on “Meet the Press.” “He’s got to decide this weekend whether he’s an American first or a Trump loyalist.”

As the public phase of the impeachment probe enters its second week, Republicans have struggled to defend Trump’s actions.

On “Fox News Sunday,” House Minority Whip Steve Scalise (R-La.) dismissed the witnesses who have testified that they were concerned about Trump’s efforts to pressure Ukraine, arguing that “they were not all Trump administration folks.”

“They’re Schiff’s witnesses,” Scalise said, referring to House Intelligence Committee Chairman Adam B. Schiff (D-Calif.).

When pressed by host Chris Wallace on the fact that most of the witnesses are part of the Trump administration, Scalise responded that “there are a lot of people who worked in the Trump administration who have very countering views to that and they’ve not been allowed to come forward.”

In an interview with CBS News’s “Face the Nation” that was aired in full on Sunday, House Speaker Nancy Pelosi (D-Calif.) suggested that Democrats are pleased with how the process has unfolded.

“I don’t think the president has had a good week,” Pelosi told host Margaret Brennan.

Pelosi declined to weigh in on the timeline for a potential impeachment vote, saying only that there may be further depositions over the Thanksgiving holiday and that there may be “a decision or maybe they have more hearings” once Congress returns.

Democrats have also argued that Trump himself should testify and allow those his orbit to do so if he believes they may have exculpatory evidence.

“If Donald Trump doesn’t agree with what he’s hearing — doesn’t like what he’s hearing — he shouldn’t tweet,” Senate Minority Leader Charles E. Schumer (D-N.Y.) told reporters in New York on Sunday. “He should come to the committee and testify under oath. And he should allow those around him to come to the committee and testify under oath.”

Johnson, meanwhile, 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 Murphy also met with Zelensky in September, at a time when U.S. aid to the country was still being held up.

In her testimony, which was released Saturday, Williams was asked about her understanding of the timing of the freeze on the Ukraine aid.

“I had seen the update that OMB had decided or conveyed to the State Department that they were not clearing these particular congressional notifications,” Williams said of her awareness regarding Ukraine aid as of July 3, referring to a key procedural step in the administration releasing aid.

Days later, as Williams was meeting with Ukrainian national security adviser Oleksandr Danylyuk on July 9, Williams still didn’t know why the funding had been frozen, she said.

“I don’t believe it was clear, even as of July 9, what exactly was behind that in terms of was this a, you know, long-term hold or what was the motivation behind it,” Williams testified, according to the transcript. “But I was aware that there was a problem with clearing the assistance, yes.”