Antalya: Describing the Islamic State as "the face of evil", US President Barack Obama has admitted that deadly attacks in Paris were a "terrible and sickening setback" in the fight against the dreaded outfit but ruled out sending American troops into Syria for ground combat.
In the same breath, he said not allowing Syrian refugees into the US would betray American values.
Speaking at a news conference following G20 leaders' Summit here, Obama said US will continue working with other countries on a coordinated strategy to destroy the Islamic State without US combat troops.
The Islamic State has claimed responsibility of the Friday's attacks in Paris which killed 129 people and injured 350 others.
"Not because our military could not march into Syria" or Iraq and "temporarily clear out ISIL, but because we would see a repetition of what we have seen before," he said.
"If you do not have local populations that are committed to inclusive governance and who are pushing back against ideological extremes, then they resurface."
Obama said US can presumably send 50,000 troops into Syria.
"What happens when there is a terrorist attack generated from Yemen? Do we then send more troops into there?" The US-led coalition fighting Islamic State in Iraq and Syria would redouble efforts to implement its current strategy rather than moving in a new direction, he said.
He said Paris killings were a "terrible and sickening setback" in the fight against the Islamic State, also known as ISIS, ISIL and Daesh. But he insisted that the American-led strategy to "degrade and destroy" the militant group is working.
"ISIS is the face of evil," Obama said. "Our goal is to destroy this barbaric organisation."
Ruling out troops on ground as it would not help solve the terrorism problem, he said, "We have the right strategy and we are going to see it through".
The US President said military advisers have told him that ground troops "would be a mistake".
"It is not just my view, but the view of my closest military and civilian advisers, that (boots on the ground) would be a mistake," he said. US was persuading other allies to engage more deeply in the fight against the Islamic State.
He underlined the need to accept refugees from the war zones who are flooding into Europe.
"The people who are fleeing Syria are the most harmed by terrorism...they are parents, they are children, they are orphans." Obama said.
"It is very important that we do not close our hearts to these victims of such violence and somehow start equating the issue of refugees with the issue of terrorism... Slamming the doors in their faces would be a betrayal of our values," Obama said.
Syrian "refugees are the victims of terrorism." Rejecting criticism that US had underestimated the
capabilities of the Islamic State, he said its attacks have not been particularly sophisticated.
"If you have a handful of people who don't mind dying, they can kill a lot of people," he said.
"That's one of the challenges of terrorism. It's the ideology that they carry with them and their willingness to die."
Obama announced plans to streamline the process by which the US and France share intelligence information about potential terrorists, saying that the new arrangement would "allow our personnel to pass threat information, including on ISIL, even more quickly and more often."