Story highlights Temporarily protected immigrants from El Salvador have lived in the US since at least 2001

DHS has moved to end the temporary protected status for thousands this fall

Washington (CNN) New Homeland Security Secretary Kirstjen Nielsen faces her first major test on immigration policy next week with a decision that could force upwards of 250,000 Central Americans to leave the United States or scramble to find a way to stay.

Monday is the deadline for deciding the future of a protected status for nationals of El Salvador, and the Department of Homeland Security is widely expected to announce an end to the program, which has offered work permits and the right to live in the United States.

More than 260,000 Salvadorans are covered by the program, according to US Citizenship and Immigration Services, but some experts estimate roughly 200,000 of them could be left without the protected status, based on previous department estimates. Salvadorans make up the largest share of immigrants protected by the program, and all of them have lived in the United States since at least 2001.

While the Homeland Security Department has not yet announced its decision, its actions this year have signaled a tougher approach to the program, which allows individuals from countries affected by crises like natural disasters, war and epidemics to stay in the US and work without being deported. The "temporary protected status," as it is known, lasts for about two years before needing to be renewed. El Salvador's status has been continually renewed since 2001, when it was granted after a series of earthquakes.

The pending deadline marks the first major immigration decision that will fall to Nielsen, who has thus far pledged to carry on the legacy of her predecessor and former boss, John Kelly, who is now White House chief of staff.

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