President Donald Trump has instructed the Pentagon to "annihilate" the Islamic State group in Syria in a bid to prevent escaped foreign fighters from returning home, Defense Secretary Jim Mattis said Friday.
The move to kill as many jihadists in place as possible -- rather than letting them exit a city and targeting them as they flee -- reflects an increased urgency to stop battle-hardened jihadists bringing their military expertise and ideology back to European capitals and other areas.
The president has "directed a tactical shift from shoving ISIS out of safe locations in an attrition fight to surrounding the enemy in their strongholds so we can annihilate ISIS," Mattis said, using an acronym for IS.
"The intent is to prevent the return home of escaped foreign fighters."
Trump, who campaigned on a pledge to quickly defeat IS, signed an executive order soon after taking office giving his generals 30 days to come up with a revised plan to wipe the jihadists out.
The review resulted in the new "annihilation campaign" and saw commanders gain greater autonomy to m ake battlefield decisions.
Critics of Barack Obama's administration frequently complained of White House micromanagement and a lengthy approval process causing delays on the ground.
The US-led coalition has been battling IS since late summer 2014.
Mattis said IS has lost 55 percent of the territory it once held in Iraq and Syria and over four million people have been liberated.