Sen. Bob Corker, R-Tenn., hit back at President Trump's claims he is retiring because he had "zero chance" of winning re-election in 2018.

"When I made the decision not to run, I was in a dominant position," Corker told CNN. "I had more money in the bank than any Republican incumbent. My numbers in the state were very, very strong. And so that's just not true."

"There wasn't even anybody announced that I assure you ever in the history of the world is going to be a United States senator," he added.

Rep. Marsha Blackburn, R-Tenn., former congressman Stephen Fincher, ex-head of Americans for Prosperity-Tennessee Andy Ogles, and frequent candidate Larry Crim have since declared their intentions to contest the GOP primary for the seat.

Corker, however, acknowledged there had been an "erosion" of support for him over the last six weeks since he announced in September he would not to seek another term.

"I don't really care what comes out of the White House," he said. "It's sort of a daily silliness."

Corker would not comment on Trump's "love fest" characterization of Tuesday's GOP Senate lunch nor on whether he thought the former businessman was fit to be president.

Earlier on Wednesday, Trump tweeted that "the reason [Sen. Jeff] Flake and Corker dropped out of the Senate race is very simple."

"They had zero chance of being elected," he wrote.