(CNN) -- President Barack Obama sharply defended his strategy Monday for going after ISIS amid mounting criticism that the U.S. is not doing enough to stop the terror organization that went on a killing spree in Paris last week.
He faced a barrage of tough and probing questions from international journalists at a G20 summit in Antalya, Turkey, that often put him on the defensive. In response, he repeatedly stressed confidence in his approach to Syria, where a civil war has dogged his administration for years and helped create an opening for ISIS to flourish.
"We have the right strategy and we're going to see it through," Obama said. "There will be an intensification of the strategy we have put forward, but the strategy we have put forward is the strategy that will ultimately work."
He said that airstrikes by the U.S.-led coalition have been effective in taking out key members of the terror group's leadership and that a large presence of ground troops in Syria would be a "mistake."
An increasing chorus of critics, especially Republicans, have called for a more aggressive U.S. military effort in fighting ISIS, but Obama pushed back against that call.
"It is not just my view but the view of my closest military and civilian advisers that that would be a mistake," Obama said, adding that's "because we would see a repetition of what we've seen before, which is if you do not have local populations that are committed to inclusive governance and who are pushing back against ideological extremes, that they resurface, unless we're prepared to have a permanent occupation of these countries."
Last month, Obama committed to sending "less than 50" Special Operations forces to the region.
Obama also said that the U.S. is united with France in the fight against ISIS, after a Paris terror attack that left at least 129 people dead.
"ISIL is the face of evil," Obama said. "Our goal, as I've said many times, is to degrade and ultimately destroy this barbaric terrorist organization."
"Today again I'm calling on leaders to commit the resources that this fight demands," Obama added.
Obama condemned critics who want a "religious test" for admitting refugees from Syria, blasting the idea as un-American.
He also used the charge to indirectly attack Republican 2016 presidential candidates.
"When I hear political leaders suggesting that there would be a religious test for which a person who is fleeing from a war-torn country is admitted, when some of those folks themselves come from families who benefited from protection when they were fleeing political persecution, that's shameful, that's not American," Obama said. "That's not who we are. We don't have religious tests (for) our compassion."
Florida Sen. Marco Rubio and Texas Sen. Ted Cruz, who are both running for president, are the children of Cuban immigrants and have called for increased scrutiny of refugees fleeing Syria who seek asylum in the U.S.
Obama called on world leaders to accept refugees fleeing the conflicts in Syria and Iraq, though he added that accepting refugees required "rigorous screening and security checks."
"We also have to remember that many of these refugees are victims of terrorism themselves," Obama said.
"The overwhelming majority of victims of terrorism ... are Muslims," Obama added later. "ISIL does not represent Islam, it is not representative in any way of the attitudes of the overwhelming majority of Muslims."