Donald Trump tweeted Friday morning that Texas Sen. Ted Cruz was planning an attack on him. He then questioned Cruz's religion and ties to Big Oil in comments Friday night.

"I am an evangelical. I'm a Christian. I'm a Presbyterian," Trump said to an Iowa town hall rally. In contrast, he said that while he personally liked Cruz, "not a lot of evangelicals come out of Cuba, in all fairness."

Trump may be feeling pressure from Cruz after the Texas senator snatched first place from the billionaire in a Monmouth University Poll released Monday. Cruz is also ranked first in the Washington Examiner's power rankings.

Trump went on to criticize Cruz's opposition to ethanol, saying it was because the first-term senator is loyal to the Lone Star state's oil industry who "give him a lot of money."

But for all the tough talk, Trump didn't say whether he would or wouldn't consider taking Cruz on as his vice president should he win the party's nomination.

There are less than two months until the Feb. 1 Iowa Caucus. Cruz and Trump's campaigns have said they will focus that time on connecting with voters in the primary state.