(CNN) Republican National Committee Chairman Reince Priebus said Monday that presumptive GOP presidential candidate Donald Trump's running mate should reflect diversity, be of age, gender or ethnicity.

"There has to be a degree of diversity on the ballot. Now whether it be a diversity of age, or whether it be a diversity of gender, or ethnic background, somehow or another, diversity is important in some respects," Priebus told Hugh Hewitt on his radio show. "But obviously, it's not my decision ... but I do think they're going to take their time and do it right."

Hewitt, riffing off vice-presidential speculation, added: "God bless Newt Gingrich and Sarah Palin, but we need somebody young."

Priebus also noted that since Trump, a first-time candidate, has embodied the spirit of a Washington outsider, he should also consider pairing with a "real seasoned veteran."