Republican presidential candidates are voicing strong opposition in the wake of Friday's deadly attacks in Paris to President Barack Obama 's plan to allow 10,000 Syrian refugees to enter the United States over the next year.

Their criticism comes as Republican governors say they will block Syrian refugees from entering their states, citing concerns over terrorism.

Obama, meanwhile, has stood by the plan.

"As president, my first priority is the safety of the American people, and that's why even as we accept more refugees, including Syrians, we do so only after subjecting them to rigorous screening and security checks," Obama said Monday after the G-20 summit in Turkey.

Obama also criticized Republicans for arguing that the U.S. should only admit Christian Syrians.

"That's shameful," Obama said. "That's not American. That's not who we are. We don't have religious tests to our compassion."

Here's where some of the 2016 GOP field stands on refugees as of Monday:

Ben Carson