Republican presidential candidate Senator Ted Cruz said the attacks in Paris "underscore that we are facing an enemy who is fierce, who is relentless, who is at war with us -- even if our own president doesn't understand that it is at war with us -- and who will not stop until is defeated."

"That enemy is radical Islamic terrorism," Cruz said.

"As long as we have a Commander-in-Chief unwilling even to utter the words 'radical Islamic terrorism,'" Cruz said, "we will not have a concerted effort to defeat these radicals before they continue to murder more and more innocents, whether Europeans, or Israelis, or Americans."

President Obama has said that he doesn't use the term "radical Islam" in characterizing ISIS because it grants them a religious legitimacy they don't deserve. "We are at war with people who have perverted Islam," the President said in February.

The Texas senator went on to say that Muslim Syrian refugees, "who our intelligence cannot determine if they are here to kill us or not," should not be allowed into the U.S. and should be resettled in majority Muslim nations in the Middle East.

Cruz said that on the other hand, Christians facing persecution and beheadings should be given a safe haven here.

He said that as president, he would wage a campaign of "overwhelming force" against ISIS in Syria and Iraq.

"In a Cruz administration, we would be using overwhelming air power and the Kurds as our boots on the ground, and it would be clear to any militant on the face of the earth, if you join and go ISIS, if you wage jihad against America, you're signing your death warrant."

Watch part one of the "Fox & Friends" interview above, and part two below.

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Presidential Candidates React to Paris Terror Attacks