"The GOP needs more actual argument on substance, not fake one-liners. I agreed to spar with @ChrisChristie tomorrow for a full hour on Fox at 6pm," Mr. Ramaswamy said in an Oct. 3 post on X, with Mr. Christie confirming the meeting.

However, it was later revealed that the RNC threatened to ban them from the next GOP primary debate if they took part in the discussion.

"It is very disappointing that we were threatened with exclusion from the Miami debate and future debates for trying to have a more complete dialogue with each other and the voters," Mr. Christie said in an Oct. 3 X post.

"Every campaign was offered that opportunity by Fox News and they have now been effectively banned by the RNC," he said.

"I am always up for those discussions—it's a shame the RNC and @realDonaldTrump aren't."

Mr. Christie stressed the need for the GOP to have "more debates and in-depth discussion, not less."

He praised Mr. Ramaswamy for his willingness to engage with him.