The Trump administration is repurposing a mobile application - originally created to facilitate asylum appointments - into a way for undocumented migrants already in the US to "self-deport".

The app, known as CBP Home, allows migrants to submit an "intent to depart", which US Customs and Border Patrol says offers them a chance to leave without "harsher consequences".

US officials have repeatedly suggested that undocumented migrants in the country should leave voluntarily, rather than be arrested and subject to deportation.

This is the latest move in the White House's effort to dramatically overhaul the US immigration system, which has included promises of mass detentions.

Originally launched as CBP One in 2020, the mobile application was expanded during the Biden administration to allow prospective migrants to book appointments to appear at a port of entry.

At the time, officials credited the application with helping reduce detentions at the border and portrayed the technology as part of a larger effort to protect asylum seekers making the often dangerous journey.

Now, on the newly rebranded application, undocumented migrants identify themselves and declare their intention to leave the country.

In a statement, Homeland Security Secretary Kristi Noem said that by self-deporting through the app, migrants "may still have the opportunity to return legally in the future and live the American dream".

"If they don't, we will find them, we will deport them, and they will never return," she added.

The app also asks migrants whether they have "enough money to depart the United States" and whether they have a "valid, unexpired passport from your original country of citizenship".

The BBC has contacted DHS for further details about how the process works once the forms on the app are filled out.

CBP Home can also be used to apply and pay for I-94 entry and exit cards up to seven days before travel, book inspections for perishable cargo and check wait times at US border crossings.

According to DHS, the app is meant to complement a $200m (£155m) domestic and international ad campaign calling for undocumented migrants to "stay out and leave now".

The Trump administration moved quickly to scrap the CBP One app as part of a larger shift in immigration strategy. It also paused parole programmes, and an uptick in Immigrations and Customs Enforcement (ICE) raids in the country followed.

In late February, the administration said it would create a national registry for undocumented migrants and those failing to sign up could possibly face criminal prosecution.

The registration requires any undocumented migrants above the age of 14 to provide the US government an address and their fingerprints.

Experts said that the registration system will face hurdles, as it is difficult to enforce and fraught with logistical challenges.