Sen. Jeff Flake (R-Ariz.) plans to deliver a speech this week condemning President Trump's frequent attacks on the press and comparing him to Soviet dictator Joseph Stalin.

"2017 was a year which saw the truth - objective, empirical, evidence-based truth -more battered and abused than any other time in the history of our country, at the hands of the most powerful figure in our government," Flake will say in his speech, according to excerpts provided by his office

Flake, who is retiring from the Senate when his term ends next January, has said he plans to deliver a series of speeches about how Trump's presidency has impacted the country.

This week's speech will focus on Trump's tendency to attack the press, including last year when he tweeted that media outlets were the "enemy of the American People!"

"Mr. President, it is a testament to the condition of our democracy that our own president uses words infamously spoken by Josef Stalin to describe his enemies," Flake is expected to say.

The similarities to Stalin "should be a source of great shame" for senators, Flake will add.

Flake has been a frequent and vocal critic of the president. Flake has in recent days said Trump's attacks on the media damages the country's standing in the world and empowers dictators elsewhere.

Trump has labeled several media outlets "fake news" in response to unfavorable coverage, and has even vowed to host "Fake News Awards" to highlight certain reporting.

-This report was updated on Jan. 15 at 10:45 a.m.