Republican National Committee Chairman Reince Priebus called efforts to recruit an independent candidate to take on presumptive nominees Donald Trump and Hillary Clinton a "suicide mission."

"This is a suicide mission," he told CBS Sunday morning. "It is not right."

He said it could cost conservatives the White House not just for eight years but for "generations to come."

A group of Republicans opposed to Trump, including 2012 nominee Mitt Romney, are reportedly reaching out to possible candidates to run against Trump and Clinton.

Priebus said Republicans can't risk flirting with such efforts given the stakes. For example, three Supreme Court justices could retire in the next eight years, he said.