(CNN) Secretary of Defense Mark Esper said Wednesday that ISIS was not "in a resurgent state in Syria" despite a Pentagon inspector general report saying the terror group is re-surging in that country.

"I don't agree that ISIS is in a resurgent state in Syria, but that doesn't mean we haven't seen them spring up in places like Afghanistan," Esper said in an interview with Fox News, his first since becoming Defense secretary.

His comments appear to be at odds with a report from the Pentagon's Office of the Inspector General published earlier this month, which said ISIS was "re-surging" in Syria following President Donald Trump's decision to reduce troops there.

"Despite losing its territorial 'caliphate,' the Islamic State in Iraq and Syria (ISIS) solidified its insurgent capabilities in Iraq and was re-surging in Syria," the report said.

Trump initially sought to withdraw all US troops from Syria but later opted to keep a residual force in place.

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