COLUMBIA, Tenn. (AP) — U.S. Sen. Bob Corker said Friday that that it was his duty as a "respectable public official" to sharply criticize Donald Trump after the president's defense of a white nationalist rally in Virginia that left an anti-racist protester dead.

The Tennessee Republican and chairman of the Senate Foreign Relations Committee earlier this week questioned whether Trump had the stability or competence to become a successful president.

"If I'm going be a respectable public official, it had to be spoken to," Corker said. "I'm an American first."

The remark drew applause at a luncheon hosted by the Kiwanis and Rotary clubs in Columbia.

Corker's rebuke came after Trump insisted that "there is blame on both sides" for the violent clashes in Virginia and "there were very fine people on both sides." He later called efforts to remove monuments to the Confederacy an attack on America's "history and culture."

Corker said he had previously shared his concerns with the president privately, though he acknowledged that "maybe some of what I said came as a surprise to him."

"There's got to be a degree of moral clarity in what it is we say as public officials," Corker said. "I felt that that had been lacking and felt the need to speak out."

Corker told reporters earlier Friday that he'd not yet heard directly from Trump, but that he's sure the president is "very aware" of his comments that he said were aimed at getting him to focus on uniting the country.

"People expect a president to grow in his office and to step up, and I hope that's going to be the case," Corker said.

A day after Corker called for "radical changes" at the White House, the president pushed out Steve Bannon, the divisive strategist who rose from Trump's campaign to a top White House post. Corker declined to weigh in on Bannon's departure, saying that he tries to steer clear of personalities in the White House.

But Corker did voice strong support for Chief of Staff John Kelly, who he said he considers to be part of the national security team with Secretary of State Rex Tillerson, Defense Secretary Jim Mattis and National Security Adviser H.R. McMaster.

"I support all of them and they know it," Corker said.

Corker's Senate seat is up for re-election next year, but he has not yet publicly announced whether he will seek a third term.