Donald Trump said Thursday he's not thrilled with the idea of Wisconsin Rep. Paul Ryan being Speaker of the House and expressed shock that Republicans haven't found a more conservative candidate.

"I'm not thrilled, I'm not thrilled," Trump said of Ryan on the John Fredericks Show. "Not easily, I mean it's not that you are given a choice. Don't forget that you have people in Washington, Republicans that are going to be making a choice, and it looks like he is going to be the one. You saw what happens this morning and it looks like he is going to be the one. And if you have to live with it, you have to live with it, John. We can't go crazy. We can't say oh gee, I refuse to show up, or I refuse to do something."

Trump said Ryan was soft on immigration, the key issue of Trump's campaign.

"Now he's very, very weak on illegal immigration, I don't like that, you know he's an amnesty person, and you know I'm not thrilled with that," said Trump. "Because you get amnesty and you do something wrong, you get amnesty, that's not what we are all about. And other things that you mentioned. And at the same time, a very conservative group in Washington, that you like and that I like and you know it looks like they are backing him. You want to sort of have a group of people that are unified and they do need somebody.

"I'm a little surprised that somebody more conservative and tough, because they need some toughness, and smartness, and I'm a little surprised that somebody more conservative and tougher on the issues has not been chosen," said Trump. "I'm a little surprised, actually."

Trump's views on Ryan have shifted between support and criticism in recent years.

Trump told Fox And Friends in 2011, "Well, I think Boehner is doing a good job, but he's trying to get the best number he can and it looks like he's got the votes, but the really big one is going to be what Paul Ryan, who I think is also a terrific guy, just absolutely terrific, what he's trying to do, that's the long-term picture."

On Twitter earlier this week, Trump praised Ryan, saying, "Paul Ryan is far from my first choice, but a very nice guy. The Republicans should go for tough and (very) smart this time - no games!"

Still, Trump has been critical of the Wisconsin congressman in past, saying his budget would doom Republican electoral prospects.