The U.S. process for screening refugees only commences after representatives of the United Nations High Commissioner for Refugees screens and determines that an individual meets the international standard for refugees: an individual who has a “well-founded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group or political opinion, is outside the country of his nationality and is unable, or owing to such fear, is unwilling to avail himself of the protection of that country.” 
Once an individual is determined to be a “refugee” by that U.N. agency and is designated for resettlement in the U.S., the U.S. commences its process for screening such an individual before he or she is permitted to come to the U.S. On November 19, 2015, Mr. Simon Henshaw, the U.S. Principal Deputy Assistant Secretary of State for Population, Refugees, and Migration, gave a special briefing on that U.S. process.  Here is what he had to say.
The U.S. “remains deeply committed to safeguarding the American people from terrorists, just as we are committed to providing refuge to the world’s most vulnerable people. We do not believe these goals are mutually exclusive or that either has to be pursued at the expense of the other.”
“All refugees go through the most intensive security screening of any travelers to the [U.S.]. It includes multiple federal intelligence, security, and law enforcement agencies, including the National Counterterrorism Center, the FBI Terrorist Screening Center, and the Departments of Homeland Security, State, and Defense. A refugee applicant cannot be approved for travel until all required security checks have been completed and cleared.”
“Syrian refugees go through yet additional forms of security screening. . . . We prioritize admitting the most vulnerable Syrians, including female-headed households, children, survivors of torture, and individuals with severe medical conditions. We have, for years, safely admitted refugees from all over the world, including Syrian refugees, and we have a great deal of experience screening and admitting large numbers of refugees from chaotic environments, including where intelligence holdings are limited.” In addition, the Government continues “to examine options for further enhancements for screening Syrian refugees, the details of which are classified.”
The “Department of Homeland Security has full discretion to deny admission before a refugee comes to the U.S. When in doubt, DHS denies applications on national security grounds and the individual never travels to the [U.S.]. Their decisions are guided by the key principle directed by the President and affirmed throughout the U.S. Government that the safety and security of the American people must come first. The U.S. Government has the sole authority to screen and decide which refugees are admitted to the [U.S.]. Security checks are a shared responsibility between the State Department and DHS.”
“All available biographical and biometric information is vetted against a broad array of law enforcement, intelligence community, and other relevant databases to help confirm a refugee’s identity, check for any criminal or other derogatory information, and identify information that could inform lines of questioning during the interview. DHS conducts extensive in-person interviews of all refugee applicants. Biographic checks against the State Department’s Consular Lookout and Support System, known as CLASS, which includes watch list information, are initiated at the time of a prescreening carried out by State Department contractors.”
“In addition, the State Department requests security advisory opinions from the law enforcement and intelligence communities for those cases meeting certain criteria. Biometric checks are coordinated by USCIS [U.S. Customs and Immigration Service] using mobile fingerprint equipment and photographs at the time of the interview. These fingerprints are screened against the vast biometric holdings of the FBI, the integrated automated fingerprint identification system, and screened and enrolled in DHS’s Automated Biometric Identification System, which is known as IDENT.”
“Through IDENT, applicant fingerprints are screened not only against watch list information, but also for previous immigration encounters in the [U.S.] and overseas, including cases in which the applicant previously applied for a visa at a U.S. embassy. The classified details of the refugee . . . security screen process are regularly shared with relevant congressional committees.”
“The U.S. welcomed 1,682 vulnerable Syrian refugees in Fiscal Year 2015, and the President has directed his team to make preparations to admit at least 10,000 Syrian refugees in Fiscal Year 2016. Measured against more than four million Syrian refugees currently hosted in the Middle East, this is a modest but an important contribution to the global effort to address the Syrian refugee crisis.”
In addition, it has been widely reported that the U.S. screening of an individual Syrian refugee typically takes at least two years.
This account of the screening process should provide assurances to the American public that no additional procedures are necessary and that the recent bill to do that as passed by the House of Representatives is unnecessary.
 Refugee and Asylum Law: Modern Era (July 9, 2011); Refugee and Asylum Law: Office of U.N. High Commissioner for Refugees (July 10, 2011).
 The mobile units for screening Syrian refugees currently are located in Turkey and Jordan with another unit planned for Lebanon.