Religious groups in the United States have urged the White House to step up its response to the Syrian refugee crisis, with one on Tuesday calling Washington's efforts so far "disappointing."Church World Service, a global humanitarian organization that represents 37 Christian denominations, has called on the government to take in 100,000 Syrians over the next year, said Jen Smyers, who works on the group's immigration and refugee program.The US Conference of Catholic Bishops, the Lutheran Immigration and Refugee Service, and the Jewish refugee assistance agency HIAS along with secular groups have also backed that figure.Since Syria's war broke out in 2011, Washington has accepted 1,500 refugees, most of them this year, and the State Department expects 300 more by October. Four million people have fled the country since the fighting began, according to UN estimates."We've been disappointed at the current status of US leadership," Smyers said. "I think we have seen some nodding of heads and people recognizing that something needs to be done, but we're still waiting to see what that is."Smyers said Church World Service, one of nine domestic groups that partner with the federal government on re-settlements, also supports the Protecting Religious Minorities Persecuted by ISIS Act, introduced in the US. House of Representatives in March.The bill would streamline how Iraqis and Syrians targeted for their religion, gender or ethnicity apply as refugees.