In a video released on Wednesday, ISIS for the first time used a child of purported US origin to openly threaten the United States.

The boy's message seems to be a prepared speech, and mentions US President Donald Trump by name. In it, he warns that ISIS' battle will "not end" in Raqqa or Mosul but rather "in your lands."

"So get ready, for the fighting has just begun," the boy emphasized.

According to ISIS, the 10-year-old boy arrived in Syria with his mother two years ago. His father, they claim, is a member of the US military and fought in Iraq.

None of these claims have been proven true.

State Department spokesperson Heather Nauert said the video was "depraved," regardless of whether or not the boy is indeed a US citizen.

"It's another example of how wrong and evil ISIS is," she said.