Donald Trump says he was "blindsided" by Speaker of the House Paul Ryan's decision to announce he could immediatly endorse the presumptive Republican nominee for president.

In an interview with NBC's "Meet The Press" set to air Sunday, Trump told Chuck Todd that he has a good relationship with Ryan, a Wisconsin Republican. That is why he was shocked at Ryan's comments to CNN's Jake Tapper.

"I mean, to be honest. I like Paul Ryan. I think he's a very good guy," Trump said. "He called me three weeks ago, and he was so supportive. It was amazing. And I never thought a thing like this. I got blindsided by this."

Ryan said on Thursday that he was "not ready" to support Trump as the GOP's nominee. Ryan said it's up to Trump to unify the GOP and, if that happens, he'll be able to support the New York real estate mogul.

In his interview with "Meet The Press," Trump said Ryan called him after he won New York's primary and they had a nice conversation.

"He called me to congratulate me. Couldn't have been nicer. And again, I have a nice relationship with him. Don't know him well. Met him one time," Trump said. "But have a nice relationship with him. And then all of a sudden, he gets on and he does this number. So I'm not exactly sure what he has in mind. But that's okay."

Trump and Ryan are set to meet in Washington, D.C., this coming week to discuss their differences.