MANILA, Philippines -- President Obama on Wednesday angrily accused Republicans of feeding into the Islamic State's strategy of casting the United States as waging war on Muslims, saying the GOP's rhetoric has become the most "potent recruitment tool" for the militant group.

Obama was responding to recent calls from Republicans, including presidential candidates Jeb Bush and Sen. Ted Cruz (Tex.), to block Syrian refugees' entrance into the United States. Bush and Cruz have suggested welcoming Christian refugees, but not those who are Muslims.

"I cannot think of a more potent recruitment tool for ISIL than some of the rhetoric coming out of here in the course of this debate," Obama said during a news conference at a leadership summit here, using an acronym for the Islamic State.

The president said that the group "seeks to exploit the idea that there's war between Islam and the West, and when you start seeing individuals in position of responsibility suggesting Christians are more worthy of protection than Muslims are in a war-torn land that feeds the ISIL narrative."

Obama's sharp words, delivered during his stop at the Asia-Pacific Economic Cooperation summit here, underscored the enormous chasm between the president's approach to upheaval in the Mideast and those of Republicans, some of whom are seeking their party's presidential nomination next year. The president has pledged to accept at least 10,000 Syrian refugees in the coming year, but the fact that a Syrian passport was recovered from one of the assailants killed Friday during the terrorist strikes in Paris has prompted many GOP politicians to call for a halt to any such plan.

Dozens of GOP governors have said this week they will not accept Syrian refugees into their states. Along with the Republican presidential contenders who have proposed only allowing Christians from Syria into the United States, others have suggested none should be admitted in the near future.

The Fix's Amber Phillips breaks down why GOP presidential candidates are using the attack in Paris to call for limiting refugees allowed in the U.S. (Sarah Parnass/The Washington Post)

During a campaign stop in Florence, S.C., on Tuesday, Bush said: "At a minimum, we ought to be bringing people like orphans and people who are clearly not going to be terrorists. Or Christians. There are no Christian terrorists in the Middle East, they’re persecuted, they are religious minorities."

Later, at another even, Bush said disputed Obama's characterization that he doesn't have sympathy for Muslims suffering from the violence. "Well, I do," he said. "We all have sympathies for people who have been uprooted. ... But we have a duty to protect our country as well. And that’s the point."

During his remarks, Obama defended the current federal screening process for refugees, saying it takes between 18 months and two years for each applicant to be admitted. He emphasized that the people fleeing Syria have been brutalized by both the ruling government led by Syrian President Bashar al-Assad and other militant factions, including the Islamic State

"They are subjected to the most rigorous process conceivable," Obama said of those seeking asylum. "The intelligence community vets fully who they are." Standards are so stringent and cumbersome, he added, that "it's very difficult to show the kind of compassion we need to these folks suffering under the bombings of Assad and the attacks of ISIL. They are victims of this terror."

On Monday Obama had made the point -- unprompted --during a press conference in Turkey that "slamming the door shut" in the face of those seeking humanitarian assistance, or screening them on the basis of their religion, was "shameful." But speaking to reporters for the second time in two days, he made his case once more to the American public.

President Obama decried the calls from some to stop accepting Syrian refugees after the attacks in Paris, saying it would be "a betrayal of our values." (AP)

"If there are concrete, actual ideas to expand the extraordinary screening process in place, we’re open to hearing actual ideas, but that’s not what’s been going on this debate," the president added. "When candidates say we should not admit 3-year-old orphans, that’s political posturing. When individuals say we should have religious tests, and only Christians, proven Christians, should be allowed, that’s offensive and contrary to American values."

Republican efforts to judge people in the Mideast based on their religious affiliation is "counterproductive," the president said. "And it needs to stop."

The president also mocked Republicans for expressing concern about whether these refugees could pose a threat to Americans, when they have also criticized him for not taking an aggressive enough stance against Russian President Vladimir Putin or Islamic extremists.

"And I would add these are the same folks who suggested they’re so tough that just talking to Putin or staring down ISIL" will work, he said. "But they're scared of widows and orphans coming into the United States of America as part of our tradition of compassion. First, they were worried the press was too tough on them in the debates; now they're worried about 3-year old orphans. That doesn’t sound very tough to me."

Eilperin reported from Washington.