Nigerians and other foreign nationals in the United States (US) who hold temporary visas will now be required to return to their home countries to apply for permanent residency.

The US Citizenship and Immigration Services (USCIS) announced the change on Friday, stating that the policy restores the "original intent" of immigration law. 

Under the new rules, non-immigrants seeking to adjust their status to permanent residents must process applications through US consular offices abroad, under the supervision of the State Department.

According to officials, the move is intended to ensure that people who enter the US for a defined purpose, such as study, work or tourism, return home once that purpose is complete, saying exceptions will be made only in extraordinary circumstances.

READ ALSO: Nigeria on Alert as NCDC Monitors Ebola Outbreaks in Congo, Uganda

USCIS spokesman Zach Kahler said the policy aims to reduce the number of people who remain in the country unlawfully after unsuccessful residency applications. 

Kahler added that processing applications from abroad would allow the system to operate as intended and help prevent misuse of temporary visa routes.

The announcement follows earlier restrictions introduced by the US on several visa categories affecting Nigeria and 14 other countries.

USCIS stressed the adjustment would make the immigration process fairer and more efficient by aligning practice with the legal framework that governs non-immigrant entry and stay in the United States.