The US has lifted a ban on admissions to refugees from 11 countries whose applicants it designated “high-risk” and announced tougher vetting measures to weed out potential extremists and criminals.

The Trump administration on Monday refused to identify the 11 “high-risk” nations, citing “law enforcement sensitivities”. But officials with knowledge of the list said the countries included Egypt, Iran, Libya, South Sudan, Yemen, Sudan, Iraq, Mali, North Korea, Somalia and Syria, the Washington Post reported.

All but North Korea and South Sudan are Muslim majority.

Applicants from these “high-risk” countries will face more extensive background checks from US screeners, according to administration officials, and the government will move to implement what it characterized as a more rigorous model for identifying possible threats.

“These additional security measures will make it harder for bad actors to exploit our refugee programme and they will ensure we take a more risk-based approach to protecting the homeland,” Homeland Security Secretary Kirstjen Nielsen said in a statement.

“The US must continue to fulfil its obligation to the global community to assist those facing persecution and do so in a manner that addresses the security of the American people,” she said.

The new measures will include additional interviews of applicants’ family members and close scrutiny of potential ties to organized crime, US officials told reporters.

An official said the high-risk determination for the 11 nations “has nothing to do with religion”.

The enhanced security measures will also increase information sharing among the US agencies tasked with vetting refugee applicants.

The high-risk list will be reviewed every six months and countries could be added or removed based on evolving assessments of security threats to the US.

Last year, US President Donald Trump signed a directive setting the country’s annual refugee cap at 45,000, the lowest annual limit since 1980. It is one of a string of limits he imposed on the US refugee programme.

The US has admitted roughly 6,500 refugees since the 2018 fiscal year began in October compared with about 32,000 during the same period last year, according to State Department figures.

Among them, 332 refugees who have been admitted to enter America so far this fiscal year came from “high-risk” countries, compared with nearly 16,000 in the same period last year.