WASHINGTON: Migrants to the US seeking permanent residency or a green card will have to return to their home country to file their applications, the US Citizenship and Immigration Service said on Friday.

“From now on, an alien who is in the US temporarily and wants a Green Card must return to their home country to apply, except in extraordinary circumstances,” USCIS spokesman Zach Kahler said in a statement here.

He said the US was returning to the original intent of the law to ensure aliens navigate its immigration system properly.

"This policy allows our immigration system to function as the law intended instead of incentivising loopholes. When aliens apply from their home country, it reduces the need to find and remove those who decide to slip into the shadows and remain in the US illegally after being denied residency,” Kahler said.

The USCIS announced a new policy memo reiterating the fact that, consistent with long-standing immigration law and immigration court decisions, aliens seeking adjustment of status must do so through consular processing via the Department of State outside of the country.

The policy memo directed officers to consider all relevant factors and information on a case-by-case basis when determining whether an alien warrants this extraordinary form of relief.

“Nonimmigrants, like students, temporary workers, or people on tourist visas, come to the US for a short time and for a specific purpose. Our system is designed for them to leave when their visit is over,” the USCIS said.

“Their visit should not function as the first step in the Green Card process,” it said.

Following the law allows the majority of these cases to be handled by the State Department at the US consular offices abroad and frees up limited USCIS resources to focus on processing other cases that fall under its purview, including visas for victims of violent crime and human trafficking, naturalisation applications, and other priorities.

“The law was written this way for a reason, and despite the fact that it has been ignored for years, following it will help make our system fairer and more efficient,” the USCIS said.