Republican Party leaders have called on Congress to pause the resettlement of Syrians refugees in the United States. At least 26 state governors have refused to shelter Syrian refugees.

"This is a moment where it is better to be safe than to be sorry," said Paul Ryan, a Republican and the speaker of the House of Representatives. "We think the prudent, the responsible thing is to take a pause in this particular aspect of this refugee program in order to verify that terrorists are not trying to infiltrate the refugee population," he said.

The backlash against Syrian refugees in the United States has come in the wake of coordinated terrorist attacks in Paris on Friday, which killed at least 129 people and wounded hundreds more.

One of the three men who blew himself up outside of the France-Germany soccer match had reportedly traveled with a fake Syrian passport along one of the routes used by refugees to reach Europe. The other attackers were French nationals. The alleged ringleader, Abdelhamid Abaaoud, is Belgian and still at large.

The United States already has a stringent screening system in place when it comes to refugees, according to James Hathaway, an expert on refugee law at the University of Michigan. Normal procedures call for refugees to be vetted by five national agencies. Syrians are vetted by six agencies.

"These people have been screened at more levels than probably any other human beings coming into United States in recent memory," Hathaway told DW.

Few Syrians in United States

While Germany has taken in more than 100,000 Syrians this year, the United States has settled less than 2,000 since the Syrian war broke out in 2011.

"The interagency security procedure is so incredibly detailed...that they can't actually process more than that," Hathaway said of the United States.

The Obama administration has promised to take in 10,000 additional Syrians over the coming year. Steven Bucci, a national security expert with the conservative Heritage Foundation, said the White House could and should do more to screen refugees.

"The vetting process we have now is at best incomplete and at many times is skipped over and done after the fact," Bucci said. "We can't have those kinds of exceptions now."

Since the September 11, 2001, terrorist attacks, the United States has settled 784,000 refugees, according to the Migration Policy Institute. Three of the people given refugee status have been arrested for planning terrorist activities.

"Pragmatically, if you want the complete security that some of the governors seem to be talking about, we might as well cut off all the air routes into the United States and close the land borders with Canada and Mexico," Hathaway said. "Honestly, there's a greater threat there then there is from this process."

Religious test?

While Democratic presidential candidates Hillary Clinton and Bernie Sanders said they would accept refugees, two Republican presidential candidates, Texas Senator Ted Cruz and former Florida Governor Jeb Bush, have said the United States should focus on taking in Syrian Christians instead of Muslims.

"We should not be allowing Muslim refugees from countries where ISIS and al Qaeda have control of significant amounts of territory," Cruz told ABC News, using an alternative acronym for Islamic State. "Because of the inability of this administration, the inability of our intelligence sources to distinguish between who is and is not an ISIS terrorist."

When asked by CNN how authorities would determine a refugee's religion, Bush said, "You can prove you're a Christian...if you can't prove it, you err on the side of caution."

Ahmed Rehab, head of the Chicago office of the Council on American Islamic Relations, said the candidates' comments are a reflection of anti-immigrant as well as anti-Muslim sentiment within part of the Republican Party's base of support.

"This is extremely disturbing for the US, a secular nation that has always been a place that welcomes the huddled masses, the refugees and those that are facing persecution," Rehab told DW. "That's how our nation got started to begin with."

White House to veto bill

According to House speaker Ryan, the legislation being considered by Congress "will not have a religious test, only a security test." The FBI and Department of Homeland Security would certify to Congress that individual refugees are not a threat to the United States, Politico reported.

The White House has vowed to veto the legislation, saying it "would provide no meaningful additional security for the American people, instead serving only to create significant delays and obstacles in the fulfillment of a vital program that satisfies both humanitarian and national security objectives."

States left with power of the purse

At the state level, the governors have no legal power to refuse refugees, Hathaway said. The federal government runs the program in cooperation with private aid agencies across the country. State governments could, however, cut local funding for organizations that support Syrian refugees.

"They could make life uncomfortable for refugees who go there and obviously there's not an interest on the part of the federal government to send refugees to places that the governors make unwelcoming," Hathaway said.

Settlement agencies rely on public funding to find apartments, jobs and provide language training to refugees, according to Rehab, who previously served as vice president of RefugeeOne, an organization in Chicago that helps refugees get settled in their new communities. Cutting this funding would only hurt US national security, he said.

"Integration and empowerment of the newcomers is the greatest sort of protection against radicalization and marginalization," Rehab told DW.