Dr. Sebastian Gorka, special assistant to President Trump, says the United States is not afraid of ISIS, as they are cowards, not monsters.

"We don't use the word 'monsters' because monsters are mythological. Also they're something to be afraid of. We're not afraid of these people. These are cowards," Gorka told Bill Hemmer on "America's Newsroom."

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Alleged suicide bomber Salman Abedi detonated a bomb at an Ariana Grande concert at Manchester Arena on Monday night, killing 22 people and wounding dozens more. ISIS has claimed responsibility for the act.

England has since raised the terror alert level to its highest level of "critical," meaning more attacks may be imminent.

Gorka said Trump was right to call the terrorists "losers."

They are "pathetic, cowardly losers" and a "death cult," Gorka echoed.

The White House staffer noted modern terrorists use "very simplistic tactics" to target "the heartland of what they call the infidel," as opposed to Al Qaeda, which preferred more showy displays of violence.

This fact means we are in the next phase of terrorism, Gorka, who serves on the national security advisory staff, warned.

The Manchester attack heralds "guerilla warfare" coming to the streets of the Western world, he said.

However, hope is not lost, Gorka assured, since President Trump is committed to obliterating ISIS just as the U.S. defeated the Nazis.

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