The US has announced that in January 2019 it will terminate a programme which gave Nicaraguan immigrants protection from deportation.
The decision will affect thousands of Nicaraguan living in the US, who will have to seek "an alternative lawful immigration status" or leave the US.
The Temporary Protected Status (TPS) designation for Nicaragua was introduced in 1999 after Hurricane Mitch devastated Central America.
It has been repeatedly renewed since.
Both the Bush and Obama administrations argued that Central American nations which were granted TPS after Hurricane Mitch could not cope with the return of thousands of their nationals and extended the programme's duration.
But critics say the programme, which was created to offer temporary protection in the immediate aftermath of a disaster, has become a permanent fixture and allowed some immigrants to stay for almost two decades by renewing their visas time and time again.
Temporary Protected Status programme
- Grants temporary visas to more than 435,000 people from 10 countries ravaged by natural disasters or war
- Applies to immigrants who came to the US during the period their countries were covered by the presidential decree
- 2,550 Nicaraguans and 57,000 Hondurans are expected to reapply for TPS
- 195,000 Salvadoreans and 46,000 Haitians are waiting for a decision on whether their TPS will be renewed
Source: Congressional Research Service
Thousands of Nicaraguans and tens of thousands of Hondurans have been living in the US for almost 20 years thanks to the TPS programme.
Under the programme, they are allowed to work and many have raised families in the United States.
But on Monday the acting secretary of the Department of Homeland Security announced that the "substantial but temporary conditions caused in Nicaragua by Hurricane Mitch no longer exist" and that its TPS designation would therefore have to be terminated.
Elaine Duke said the country's TPS designation would therefore have to be terminated. While it was due to expire in January 2018, she said it would be delayed by one year "to allow for an orderly transition".
Nicaraguans will now have until 5 January 2019 to legalise their status or leave, she said.
Hondurans in limbo
Meanwhile Honduran immigrants, whose TPS was also due to expire in January 2018, have been left in limbo as a decision on their status was delayed.
Ms Duke said she needed more information. Hondurans' TPS has been temporarily extended until July 2018 to allow US officials more time to assess conditions in Honduras.
But the Department of Homeland Security already warned in its statement that a termination of the programme was "possible".
Ms Duke said she recognised "the difficulty facing citizens of Nicaragua - and potentially citizens of other countries - who have received TPS designation for close to two decades" and called on the US Congress "to enact a permanent solution for this inherently temporary programme".
By 23 November, the Department of Homeland Security will have to make a decision on whether to extend protective status for 46,000 Haitian immigrants granted TPS after the 2010 earthquake.
A decision on El Salvador's status, which was given TPS after its 2001 earthquake, is due on 8 January 2018.