Sen. Bob Corker took President Donald Trump to task on Friday for asserting political pressure on the Justice Department and Attorney General Jeff Sessions.

“Like me, most Americans hope that our justice system is independent and free of political interference,” Corker, the Tennessee Republican who chairs the Senate Foreign Relations Committee, said in a statement.

“President Trump's pressuring of the Justice Department and FBI to pursue cases against his adversaries and calling for punishment before trials take place are totally inappropriate and not only undermine our justice system but erode the American people’s confidence in our institutions,” Corker said.

Trump told reporters at the White House on Friday that he is “disappointed” with the Justice Department and won’t rule out firing Sessions, if Sessions won’t investigate Democrats.

“Honestly, they should be looking at the Democrats,” Trump said before departing the White House on a 12-day trip to Asia.

Trump wants the Justice Department and FBI to investigate Hillary Clinton’s campaign, in response to a newly published book excerpt from former acting Democratic National Committee Chair Donna Brazile. The excerpt says the Clinton campaign was improperly running the party during the 2016 primaries.

In a series of morning tweets, Trump seized on Brazile’s article that said the DNC became financially dependent on Clinton during the 2016 primary to the detriment of challenger Bernie Sanders, a Vermont senator.

“Everybody is asking why the Justice Department (and FBI) isn’t looking into all of the dishonesty going on with Crooked Hillary & the Dems,” Trump tweeted.

“At some point the Justice Department, and the FBI, must do what is right and proper. The American public deserves it!” he said in another tweet.

In a separate tweet, Trump suggested Thursday that the terror suspect accused of killing eight people in New York earlier this week should get the death penalty.

Corker and Trump have been entangled in a public and increasingly bitter feud in recent weeks.

The spat escalated last week, with Trump blasting Corker on Twitter for fighting tax reform. He added that Corker, who will leave the Senate when his current term is over at the end of next year, "couldn't get elected dog catcher in Tennessee" and insisted Corker chose not to seek re-election because Trump refused to endorse him.

MORE: Corker says he doesn't regret Trump feud

Corker hit back hard, saying Trump was “devolving” as president and that he is not a role model for children.

Corker has insisted his disagreement with Trump won’t impact his work as chairman of the Foreign Relations Committee.

USA TODAY and The Associated Press contributed to this story.