The Trump administration on Friday proposed an unprecedented series of new fees for asylum-seekers and immigrants hoping to stay in the US, aiming to become one of just four countries in the world to charge for an asylum application.

Under the proposal, a new $50 fee would be imposed on asylum applications, citizenship applications would see a $500 price hike, and a new fee would be added for certain immigrants who entered the US as children to renew protections.

The US has never before charged for asylum and, if enacted, the proposal issued Friday would make the country one of only four in the world to do so, joining Iran, Fiji, and Australia. It appears to be the latest move by the Trump administration to overhaul the asylum process and the immigration system itself, a focus of the president’s since taking office.

"This marks a dark chapter in America's history as a place of refuge," said Krish O'Mara Vignarajah, president and CEO of Lutheran Immigration and Refugee Service. "It also puts us in a club of only four countries who charge the most vulnerable asylum seekers to apply for protection, which may be prohibitively expensive for certain families who have spent their entire savings just to reach our border."

The fee increases, which were first reported by BuzzFeed News, are included in a proposed rule set to be formally published in the Federal Register next week and will be subject to public comment before it is enacted, which could result in changes to the rule.

US Citizenship and Immigration Services, which is primarily funded by immigrants’ applications, such as filing for a green card or work permit, is required to review its fee structure every two years.

“USCIS is required to examine incoming and outgoing expenditures, just like a business, and make adjustments based on that analysis. This proposed adjustment in fees would ensure more applicants cover the true cost of their applications and minimizes subsidies from an already over-extended system,” said Ken Cuccinelli, acting director of USCIS, in a statement.

Specifically, the rule would add a $50 fee for those looking to apply for affirmative asylum applications filed from within the US. There is currently no fee to enter an “affirmative asylum” application. The new fee would not apply to those who claim a fear of persecution at ports of entry or those who apply for the protections while in deportation proceedings. There would be no waiver for those who cannot afford to pay the $50 fee.