(CNN)Republican National Committee Chairman Reince Priebus said Sunday that no matter the convention-floor machinations, the GOP nominee will be one of its three current presidential candidates.
RNC chief: 'Our candidate is someone who is running'
"Our candidate is someone who is running," Priebus said in an interview with CNN's Jake Tapper on "State of the Union."
He downplayed the possibility of an alternative like House Speaker Paul Ryan emerging after several ballots in a contested convention in Cleveland.
"Here's the thing: If anything like that were to happen, which I think is highly, highly, unlikely -- I think our candidate is someone who's running, OK? That's pretty obvious -- but No. 2, even if something like that were remotely possible, that candidate would actually have to have a floor operation and an actual campaign going on with the delegates to make something like that possible, and Paul's not going to do that," Priebus said.
As for Ryan, Priebus said, "He doesn't want to do it. I know Paul very well."
If Priebus is right, it would mean the Republican field won't expand beyond Donald Trump, Texas Sen. Ted Cruz and Ohio Gov. John Kasich, even if Trump fails to secure the 1,237 delegates necessary to claim the nomination on the first ballot at the convention in Cleveland.
Priebus also said he has talked to Trump and the GOP's other candidates about tone and tenor.
"Candidates have to watch their mouth. They have to watch their tone and tenor. The only way you can be the party of the open door is to keep that in mind," he said.
And Priebus said he's happy Trump "clarified his comments" after stepping into controversy by suggesting that women who undergo abortions should be punished.
Asked on NBC's "Meet the Press" if Trump is the party's strongest candidate, he said: "I don't know."
"Listen, I don't worry about who is the strongest candidate," Priebus said. "Obviously, we have our own conversations here. But the fact is is that we're here, prepared to support whoever the eventual nominee is, with the biggest, best Republican National Committee that we've ever put together."