President Barack Obama made clear Monday he disagrees with critics who believe he should send thousands of U.S. military troops to Iraq and Syria to counter the Islamic State, after the terrorist group claimed responsibility for the deadly attacks in Paris.

A defiant Obama said conventional military strategies and operations will not work against the violent extremist group, also known as ISIS or ISIL, and warned Republican lawmakers and others that “we play into their hands when we act as if ISIL is a state.”

“This is not what’s going on here,” Obama said during a news conference from the G20 summit in Turkey. “These are killers.”

Lawmakers such as Senate Armed Services Chairman John McCain, R-Ariz., and 2016 presidential candidate Lindsey Graham, R-S.C., are calling for a different strategy that includes American ground forces.

“I think we have to have a strategy and that entails American boots on the ground along with a coalition force,” McCain said Monday on MSNBC. “… If we don’t, we’re going to see more attacks such as we saw in Paris and Beirut and the Russian airliner. This is a failed strategy or a nonexistent strategy.”

Obama: US Must Accept Syrian Refugees

McCain, who lost the presidency to Obama in the 2008 election, said without a more aggressive U.S. military strategy against ISIS, it is merely “a matter of time before there’s an attack on the United States of America.”

Speaking to reporters in Antalya, Turkey, Obama forcefully defended his strategy, which has focused on U.S. airstrikes and special operations missions in Syria and Iraq. Obama’s approach also provides training, equipment and other assistance to local forces in both countries.

The president argued his strategy “is working.” He pointed to recent operations led by Syrian opposition and Iraqi forces that have caused ISIS to lose territory. Doing so, he said, weakens the group’s argument that it is building a caliphate across the Levante, a major selling point that helps it attract disaffected Muslims from the Middle East to Europe.

Reporter to Obama: ‘Why Can’t We Take Out These Bastards?’

Obama made clear he remains opposed to a large-scale military operation featuring tens of thousands — or more — U.S. ground forces in Iraq or Syria. He indicated his top military advisers continue warning him that kind of mission would be ineffective.

Obama called for the U.S. and its allies to increase information sharing about ISIS and its potential plans, and repeated White House officials’ weekend pronouncements of an “intensification” of airstrikes and other tactics already being employed.

The president also said the United States and other Western nations “can and must” accept refugees from Syria and nearby nations. Despite concerns that doing so could open the U.S. to Paris-like attacks, Obama said such refugees will undergo “rigorous screening” and security checks before crossing borders into America.

He denounced critics who are trying to score political points from the Paris attacks, saying the U.S. “cannot afford to play the same political games.”

“This is not an abstraction. When we send troops in, they get killed, they get injured,” Obama said sternly. “And our country spends hundreds of billions of dollars.

“It’s best that we don’t shoot first and aim later,” the president said. “It’s important for us to get the strategy right, and the strategy we’re pursuing is the right one.”

Ryan Calls for Classified Briefings After Paris Attacks (Audio)

Related:

Capitol Police ‘On Highest Alert’ After Paris Attacks

Ryan Calls for Classified Briefings After Paris Attacks

See photos, follies, HOH Hits and Misses and more at Roll Call’s new video site.

Get breaking news alerts and more from Roll Call in your inbox or on your iPhone.