Sen. Amy Klobuchar (D-Minn.) on Sunday sharply criticized President Trump’s response to Russian interference in U.S. elections, saying that the president “makes it worse by calling it a hoax.”

Trump had a lengthy phone call with Russian President Vladi­mir Putin on Friday. After being repeatedly asked by reporters whether he raised the issue of election interference or warned Putin not to do it again, Trump eventually acknowledged the issue, saying, “We didn’t discuss that.”

Klobuchar, who is running for the 2020 Democratic presidential nomination, said Sunday that there is “ample evidence” that Trump is not concerned about the possibility that Russia may try to interfere in the next election. She accused Trump of dismissing the seriousness of the issue.

“This was actually an invasion of our democracy, okay?” Klobuchar said on CNN’s “State of the Union.”

U.S. national security officials have been preparing for Russian interference in 2020 by tracking cyberthreats, sharing intelligence about foreign disinformation efforts with social media companies and helping state election officials protect their systems against foreign manipulation.

But Trump has repeatedly rebuffed warnings from senior aides about Russia and sought to play down the country’s potential to influence American politics.

In a Friday tweet describing the call, Trump said he and Putin discussed the “Russian Hoax,” referring to special counsel Robert S. Mueller III’s investigation into whether Trump’s campaign cooperated with Russia during the 2016 election.

But Klobuchar said Sunday that Trump’s wording gave the false impression that the entire issue of Russian interference was a fabrication.

She also pointed to reports that acting White House chief of staff Mick Mulvaney told then-Homeland Security Secretary Kirstjen Nielsen that she should pay more attention to immigration and border security than to Russian interference because those were the issues the president cared about.

“That is wrong, and he then makes it worse by calling it a hoax. I think we need to protect our nation’s security,” Klobuchar said.

Another 2020 candidate, Rep. Eric Swalwell (D-Calif.), also criticized Trump for not mentioning election interference during his phone call with Putin.

Asked during an appearance on CBS News’s “Face the Nation” whether he stands by his previous claim that Trump is an “agent of Russia,” Swalwell replied, “I think he acts on their behalf.”

“Instead of calling the Russian president saying, ‘Don’t do this again,’ he talked to him for an hour and a half and said that the Russian president was smiling,” Swalwell told host Margaret Brennan. “I mean, that is just nutty, Margaret. That is putting the Russians’ interests ahead of the United States’ interests.”

Trump told reporters on Friday that while he and Putin were discussing the conclusion of Mueller’s investigation, Putin “actually sort of smiled when he said something to the effect that it started off as a mountain and it ended up being a mouse.”

Secretary of State Mike Pompeo also fielded questions Sunday about Trump’s phone call with Putin. Asked on “Face the Nation” why Trump did not raise the issue of Russian interference, Pompeo demurred.

“Well, you’ll have to ask the White House that question,” he said.

Pompeo went on to defend the Trump administration’s efforts to prevent future election interference, mentioning other countries in addition to Russia.

“We’re working diligently to ensure that the elections in 2020 aren’t interfered with by Russia, by Iran, by North Korea or anyone else,” Pompeo said. “We have enormous resources deployed against that challenge. And the American people should be sure that their government is working hard to keep our election safe and secure.”