Sen. Ted Cruz, R-Texas, reiterated his view on Monday that Donald Trump will not win the GOP presidential nomination.

At a town hall in the key early voting state of Iowa, Cruz was asked by an audience member why Cruz hasn't gone after Trump. 

"I don't think it's good advice for us to get in the business of blasting each other," Cruz told about 110 people at a community college in Coralville, Iowa. "I don't believe Donald Trump is going to be our nominee. I don't believe he'll be our president."

Trump had made a similar comment in a radio interview in early October, predicting, "I don't believe Donald is going to be the nominee and I think in time the lion's share of his supporters end up with us."

Except for a few polls showing Ben Carson leading the GOP presidential field in the last few months, Trump has largely been GOP voters' favorite candidate since last summer. 

A CBS News poll released last week found 30 percent of GOP voters in Iowa said they would support Trump. A Reuters/Ipsos poll released over the weekend, however, found that Trump's support among Republicans has fallen 12 percentage points in less than a week. 

The CBS poll also found that Cruz has surged in Iowa to second place, with 21 percent of GOP voters there saying they would back him. A Quinnipiac University survey from last week also found Cruz came within 2 percentage points of Trump in Iowa.

Trump has been heavily criticized over the last week because of his repeated claims about Muslims cheering the 9/11 attacks in New Jersey in 2001 and because he appeared to mock a New York Times reporter who has a physical disability.