Foreigners seeking to adjust their immigration status in the United States to secure green cards will ​have to do so from outside the country via ‌the State Department, the US Citizenship and Immigration Services said on Friday, in a move criticised by aid groups.

USCIS announced the move in a ​policy memo, which directed officers to consider relevant factors and ​information on a case-by-case basis when determining whether extraordinary ⁠relief is warranted.

“An alien who is in the US temporarily ​and wants a Green Card must return to their home country ​to apply,” said the US Department of Homeland Security, which has oversight of USCIS.

“This policy allows our immigration system to function as the law intended ​instead of incentivising loopholes.”

The USCIS said the new policy will ​free up agency resources to focus on processing other cases.

HIAS, an aid group ‌that ⁠provides services to refugees, among other groups of immigrants, said USCIS was forcing survivors of trafficking and abused and neglected children to return to the dangerous countries they fled to ​process their applications ​for green cards ⁠, granting them permanent residency in the US.

Friday’s policy change is the latest in a series of ​steps taken by US President Donald Trump over the ​last year ⁠to tighten migration to the United States.

Last year, the Trump administration moved to shorten the duration of visas for students, cultural exchange visitors and ⁠members ​of the media.

In January, the State Department ​announced that it had revoked more than 100,000 visas since Trump took office the ​year before.