Trump rejects criticism of his proposal to ban Muslims from US, comparisons to Hitler

An overflow crowed fills the hangar deck of the USS Yorktown as Republican presidential candidate, businessman Donald Trump, speaks during a rally coinciding with Pearl Harbor Day at Patriots Point aboard the aircraft carrier USS Yorktown in Mt. Pleasant, S.C., Monday, Dec. 7, 2015. (AP Photo/Mic Smith) (The Associated Press)

Supporter Erich Schmid, center, from Hilton Head, S.C., waits with other supporters to hear Republican presidential candidate, businessman Donald Trump, speak during a rally coinciding with Pearl Harbor Day at Patriots Point aboard the aircraft carrier USS Yorktown in Mt. Pleasant, S.C., Monday, Dec. 7, 2015. (AP Photo/Mic Smith) (The Associated Press)

Donald Trump is rejecting criticism that his proposal to ban Muslims from entering the U.S. is un-American and has critics comparing him to Adolf Hitler.

Trump said Tuesday that what he's proposing is "no different" than President Franklin Roosevelt — "who was highly respected by all" despite his wartime measures that included putting Japanese-Americans in internment camps in the U.S.

Trump told ABC's "Good Morning America" that banning Muslims is warranted because the U.S. is essentially at war with Muslim extremists who have launched attacks, including last week's mass shootings in San Bernardino, California, that killed 14.

"We are now at war," Trump said, adding: "We have a president who doesn't want to say that."

Trump's proposal has been denounced by many of his fellow Republican presidential candidates.