Former New Jersey Gov. Chris Christie won't run against Donald Trump on a third-party "unity" ticket with No Labels in the 2024 presidential race, he said on Wednesday.

Christie had challenged the former president for the Republican nomination but exited the race in January. He was the most vocal Trump critic of the GOP candidates.

"I appreciate the encouragement I've gotten to pursue a third-party candidacy," he said in a statement to ABC News and other outlets.

"While I believe this is a conversation that needs to be had with the American people, I also believe that if there is not a pathway to win and if my candidacy in any way, shape or form would help Donald Trump become president again, then it is not the way forward," he said.

Christie has also spoken disapprovingly of Trump's expected rematch with President Joe Biden in the general election.

"We have two awful choices here, in my view," he said on ABC's "The View" last month.

He said much the same in a February sit-down with ABC News anchor George Stephanopoulos.

"The one thing I can tell you for sure is I don't know what I'm gonna do in November. But I'm not voting for Donald Trump, under any circumstances," he said then.

In that interview, he also left the door open to potentially joining No Labels, which has been seeking to woo various potential candidates for a bipartisan ticket to run against Trump and Biden in the fall.

That effort has, to date, been unsuccessful.

A source close to Christie said he took No Labels very seriously -- commissioning polls and talking to donors in recent weeks -- but ultimately thought there wasn’t a viable path to the presidency and that him running third-party could help elect Trump.

Though Christie told Stephanopoulos last month that "if there was ever a time in our lifetime when a third-party candidate could make a difference, I think it's now" -- he also said such an effort must be realistic.

"What I've said in the past is that I'd have to see a path for anybody -- not just me -- but I think anybody who would accept that would need to see a path to 270, 270 electoral votes," he said.