Story highlights Katrina Pierson argued that the onus was on Paul Ryan, not Donald Trump, to bring about party unity

Pierson also took shots at John McCain and Mitt Romney

Washington (CNN) A national spokesperson for Donald Trump's campaign said Friday that if House Speaker Paul Ryan can't come around to supporting Trump as the Republican presidential nominee, he's no longer fit to hold his current position.

In an interview on CNN's "New Day," host John Berman asked Trump spokesperson Katrina Pierson whether Ryan was fit to retain the speakership if he can't get behind Trump as the GOP standard-bearer.

"No, because this is about the party," Pierson replied. "The last two presidential cycles we were told John McCain was a conservative. His conservative review score card is a 37%. We were told Mitt Romney was a conservative and he was pro-abortion, pro-gay marriage, pro-adoption, gave us Obamacare. And we were told to hold our noses and vote for the sake of the party. These same people are now telling us that because their guy didn't win, they want to hurt the party. The issue here isn't about Donald Trump -- if you can't hold yourself to the standard you hold everyone else to, the problem is with you."

If Paul Ryan doesn't come around to support Trump, he's not fit to be Speaker -- Donald Trump campaign spokesperson https://t.co/Nz8n33TUiq — New Day (@NewDay) May 6, 2016

Pierson also argued that the onus was on Ryan, not Trump, to bring about party unity -- contradicting Ryan, who said Thursday to CNN's Jake Tapper that in addition to being unable to support Trump right now , "the bulk of the burden on unifying the party will have to come from our presumptive nominee."

"He's speaker of what, just speaker of the House of Representatives?" Pierson shot back. "We are a party. Paul Ryan needs to be -- he is a leader of the party right now; Donald Trump is only the presumptive nominee. He's not the nominee until 1,237. So really, it's incumbent on Paul Ryan to help bring party unity."

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