Republican National Committee Chairman Reince Priebus cautioned supporters of Donald Trump who vocally disapprove of the GOP's delegate allocation and selection process.

"By the way, this is a nomination for the Republican Party," Priebus told 620 WTMJ in Wisconsin. "If you don't like the party, then sit down. The party is choosing a nominee."

Priebus said he does not think Trump will run as a third-party candidate, and added that he expects all remaining Republican candidates to support the party's nominee.

Asked by radio host Charlie Sykes whether the nominating rules would change from those set at the previous convention, Priebus sounded disgruntled.

"Well that was the last convention," Priebus replied. "The rules that people are talking about were the rules adopted by the Romney delegates in 2012. So I find it amazing that people would like to adopt the Romney rules to apply to the convention, which will largely be made up of Cruz and Trump delegates. Now, I don't think major changes are going to take place, but I don't get to write the rules."

Priebus insisted that, "I'm not in favor of changing the rules," but seemed to suggest that his party was moving toward the way it formerly chose a nominee many years ago. He also appeared to hint that the primaries and caucuses may not be as binding for the delegates as some have come to expect.

"[S]omewhere along the line, the people decided wouldn't it be a good idea if we expanded the interest here and had statewide primaries and caucuses and then we would tie the hands of the delegates for just one — just one — vote. And then after that vote, they could go back to the old way," Priebus said. "That's what's going on here."

Priebus' comments come as Wisconsinites head to the polls to cast a vote in a primary that could send the GOP hurtling toward a contested convention or move Trump several inches closer to securing the nomination before the convention begins.