Updated at 11:41 a.m. | The feud between President Donald Trump and Senate Foreign Relations Chairman Bob Corker boiled over Tuesday, trading sharp barbs and insults just hours before they were set to share a room for a Republicans-only meeting.

Corker again questioned if Trump is suited and qualified for the presidency and Trump dubbed the retiring senator a “lightweight” who couldn’t win election to low-level office in his native Tennessee.

After weeks of presidential jabs at Corker and other Senate Republicans, Trump is slated to make his first appearance at the weekly Senate Republican conference to stress the importance of passing a tax overhaul bill and other parts of their shared agenda. But the president — and Corker — made things even more awkward before he makes the short drive to the Capitol around midday.

Corker told Fox News he plans to attend the meeting.

Schumer to Trump: ‘Stop Tweeting, Start Leading’

The back-and-forth began when Corker appeared on NBC’s “Today Show” and again voiced concerns about the president, saying “there are people around him that work in an effort to contain him.”

Hours later, the duo was still trading barbs.

CNN caught up with Corker in a Senate office building hallway following a pair of Trump tweets slamming the senator anew.

“You wouldn’t support him again?” Corker was asked.

“No, no way,” he said.

“I think the things that are happening right now that are harmful to our nation, whether it’s the breaking down of — we are going to be doing hearings on some of the things that he purposely is breaking down — relationships we have around the world that have been useful to our nation,” Corker said, referring to the Foreign Relations panel he chairs.

“But I think at the end of the day, when his term is over, I think the debasing of our nation, the constant non-truth telling, just the name-calling,” he said. “I think the debasement of our nation will be what he’ll be remembered most for, and that’s regretful.”

Trump fired back minutes later, tweeting in a pair of posts: 

“Sen. Corker is the incompetent head of the Foreign Relations Committee, & look how poorly the U.S. has done. He doesn’t have a clue as….

“….the entire World WAS laughing and taking advantage of us. People like liddle’ Bob Corker have set the U.S. way back. Now we move forward!”

Sen. Corker is the incompetent head of the Foreign Relations Committee, & look how poorly the U.S. has done. He doesn’t have a clue as…..

— Donald J. Trump (@realDonaldTrump) October 24, 2017

…the entire World WAS laughing and taking advantage of us. People like liddle’ Bob Corker have set the U.S. way back. Now we move forward!

— Donald J. Trump (@realDonaldTrump) October 24, 2017

Corker’s Republican colleagues appeared to be staying out of the line of fire. Senate Majority Whip John Cornyn declined to weigh in on the beef, telling reporters, “We need to stay focused.”

Earlier, Trump wrote that Corker helped former President Barack Obama strike the Iran nuclear deal. Trump added that Corker “couldn’t get elected dog catcher in Tennessee, is now fighting Tax Cuts”.

In a second tweet just after 8 a.m., the president alleged that Corker “dropped out of the race in Tennesse when I refused to endorse him, and now is only negative on anything Trump.” (Trump misspelled Tennessee.)

He then urged his followers to “Look at his record!” — he did not direct them to anything specific, though.

Bob Corker, who helped President O give us the bad Iran Deal & couldn’t get elected dog catcher in Tennessee, is now fighting Tax Cuts….

— Donald J. Trump (@realDonaldTrump) October 24, 2017

…Corker dropped out of the race in Tennesse when I refused to endorse him, and now is only negative on anything Trump. Look at his record!

— Donald J. Trump (@realDonaldTrump) October 24, 2017

Corker addressed the situation Tuesday morning on NBC’s Today Show.

“I think it’s fine for him to come over,” Corker said. “I do look at these things as more of a  photo op. They’re not really about substance, but more power to him.”

Corker said his worries about Trump have been “building for some time as I’ve watched the way the White House has operated.

“My concerns have continued to rise. I’m one senator who is expressing what I believe to be sincere – what I know to be sincere – concerns, and other senators may have other issues they’re dealing with,” he said.

Corker and Trump have been engaged in a war of words for several months. But the president is playing a dangerous game because Corker has warned he will not support any tax measure that increases the national deficit; he has yet to say whether he supports what the White House and congressional Republican tax writers are working on.

Corker was vetted for both vice president and secretary of state by Trump and his team. But the duo fell out of favor over the summer, after Corker questioned whether Trump has the “stability” and “competence” for the country’s highest elected office.

After announcing late last month that he will not seek re-election, Trump criticized Corker. The former Chattanooga mayor shot back with a candid interview with the New York Times.

Corker told the newspaper he is concerned that Trump is running his White House and the federal government like “a reality show.”

“He concerns me,” Corker said. “He would have to concern anyone who cares about our nation.”

Trump has gotten in a few blows of his own. He has dubbed the senator with whom he once golfed “Liddle’ Bob Corker.” 

And when the president was asked on Oct. 10 about Corker’s concerns that Trump’s brash and unsteady style could put the United States “on the path to World War III.” Instead, Trump said the country was “on the wrong path before” on the North Korea threat.

“All you have to do is have to take a look. If you look over the last 25 years, through numerous administrations, we were on the path to a very big problem, a problem like this world has never seen,” Trump said, implying Corker has been part of the perceived problem. “We’re on the right path right now, believe me.”

— Joe Williams contributed to this report.