The US has not identified the 11 countries, but said refugee applications from those nations will be judged case- by-case. They would be allowed to enter the US only after it is determined that it is in national interest.
The new "enhanced vetting" procedures for all refugees include measures such as collecting additional biographical and other information to better determine whether refugees are being truthful about their status, improving information- sharing between agencies, stationing fraud detection officers at certain locations overseas and training screeners to weed out fraud and deception.
The new measures are part of the administration's effort to raise national security standards for all persons traveling to the US, and they are designed to intensify screening in order to keep nefarious and fraudulent actors from exploiting the refugee process to enter the country, said Acting Secretary of Homeland Security Elaine Duke.
"The security of the American people is this administration's highest priority, and these improved vetting measures are essential for American security," said Duke.
More From This Section
As a result of the review, the US government is implementing programme enhancements to raise the bar for vetting and screening procedures, including but not limited to: increased data collection to more thoroughly investigate applicants, better information sharing between agencies to identify threat actors and new training procedures to strengthen screener ability to detect fraud and deception.
In a fact sheet, the State Department said an inter- agency process concluded that additional in-depth review is needed with respect to refugees of 11 nationalities previously identified as potentially posing a higher risk to the US.
Admissions of following-to-join refugees will resume once those enhancements have been implemented, it said.
Despite the new policy, the US will continue to resettle more refugees than any other country in the world, and will continue to offer protection to the most vulnerable refugees while upholding the safety and security of the American people, the State Department said.
The US remains the world's leader in humanitarian assistance to refugees and displaced persons, providing more than USD 8 billion in fiscal 2017, it said.
"After three failed attempts to advance an unconstitutional Muslim Ban, President Trump continues to promote prejudiced policies, this time by implementing restrictive guidelines against refugees who have been forced to flee their homes because of unspeakable acts of violence and war," Congressman Joe Crowley said.
"Refugees who come to the US already face a rigorous and thorough vetting process that often takes years to complete. Shutting the door to these individuals does not make our nation stronger or more secure. In fact, it diminishes our standing on the world stage and robs the US of its moral leadership," he said.