As many as 200,000 Salvadoran immigrants living in the United States will no longer be allowed to stay after the Trump administration announced the end to their protected status.
The Central Americans had been permitted to stay following a devastating earthquake in 2001, under Temporary Protected Status, or TPS.
In the 17 years that have followed, every administration has extended their window to stay, including the Obama administration in September 2016.
But new Homeland Security Secretary Kirstjen Nielsen determined Monday that the "substantial disruption of living conditions caused by the earthquake no longer exist," according to the Department of Homeland Security.
The move could force those who had been protected under TPS to leave the U.S. by September 2019 or face deportation.
DHS states that the Salvadoran immigrants have 18 months until the official termination, in an effort to give them time to arrange for departure and for El Salvador to "prepare for the return and reintegration of its citizens."
The decision also gives the Salvadorans time to apply for other legal avenues to continue living in the United States. Last year, DHS also announced that they had ended TPS for Haitian and Nicaraguan citizens living in the U.S.
Salvadorans have been, by far, the largest beneficiaries of the program, which provides humanitarian relief for foreigners whose countries are hit with natural disasters or other strife.
The new DHS decision produces a serious challenge for El Salvador, a country of 6.2 million people whose economy counts on money sent by wage earners in the U.S. Over the past decade, growing numbers of Salvadorans -- many coming as families or unaccompanied children -- have entered the United States illegally through Mexico, fleeing violence and poverty.
Nielsen, who faced a Monday deadline for a decision, determined that El Salvador has received significant international aid to recover from the earthquake and that homes, schools and hospitals there have been rebuilt. Homeland Security also said more than 39,000 Salvadorans have returned home from the U.S. in two years, demonstrating El Salvador's capacity to absorb people.
The Associated Press contributed to this report.