But Trump, who endorsed Romney at an event earlier this month, suggested that Romney shouldn't shy away from heralding his success.

"If you look at Michigan, what's happened in Michigan, he was 15 points behind and now he's leading," Trump said.

The real estate mogul went on to predict a strong showing for his candidate in Tuesday's primaries. Recent polls show Romney poised for a comfortable win in Arizona, but locked in a close battle in the pivotal Michigan primary.

"I think he's doing really well and I think he's going to win Michigan and I think he's going to win Arizona and win Arizona big," Trump said.

Trump also dismissed President Obama's green energy proposals as "almost not serious" during the interview, and described protests in Afghanistan over the burning of copies of the Quran — which have resulted in the deaths of two Americans —- as "a total lack of respect for our country and our leadership."

"What are we doing there? These people hate us. As soon as we leave it's all going to blow up anyway," Trump said.