The Trump administration has announced the end of DACA — unless Congress can act to save it

The Trump administration on Tuesday announced it would end a government program that protects children who were brought to the United States illegally from being deported — but it’s essentially leaving Congress a six-month window of time to try to save it.

The legal shield is known as Deferred Action for Childhood Arrivals, or DACA, and since its enactment in 2012, it has allowed roughly 800,000 undocumented young adults to live in the United States and obtain work authorizations every two years.

On the campaign trail, Trump pledged to terminate the program — and as president, he trotted out his attorney general, Jeff Sessions, to announce its long-rumored end. In a speech at the Justice Department this morning, Sessions described DACA as “executive amnesty” and he slammed the Obama administration, which created it, for ignoring the “rule of law.”

“This does not mean they are bad people,” Sessions said of immigrants, “it means we are properly enforcing our laws as Congress has passed them.”

In practice, implementation is complicated. Those previously approved under DACA, with the permission to work in the United States, can continue to work without interruption until those approvals expire. And those who have already applied for protection or are seeking renewals will still have their applications considered by the U.S. government.

For those whose permits are set to expire before March 5, 2018, though, the U.S. government will also allow them to renew their DACA status — provided their applications are received before Oct. 5, 2017. Currently, there are about 201,000 young adults whose authorizations are set to expire this year, officials at the Department of Homeland Security explained Tuesday.

Otherwise, beginning today, the U.S. government isn’t going to consider any new DACA applications, leaving still hundreds of thousands of its beneficiaries, known as Dreamers, in legal limbo.

On one hand, the delay on enforcement gives Congress some time to decide whether to preserve the program by writing a law. Absent that, though, these Dreamers would be at risk for deportation — even as government officials stressed Tuesday they are not going to target these young adults in the future.

Tech giants like Apple, Facebook and Google are no doubt going to blast the Trump administration’s decision: Last week, those executives joined more than 400 other business leaders in calling on the president to preserve DACA.

Apple CEO Tim Cook, who previously (and privately) pressed Trump on the issue, said on Sunday that 250 of his “co-workers” would be affected by the change. Microsoft indicated that about 27 workers spanning fields like finance and sales would be hurt from Trump’s move.

Even congressional Republicans — including House Speaker Paul Ryan — previously urged the president to leave the program in place and cede a decision on its fate to lawmakers on Capitol Hill. Congress still has a chance to codify DACA into law, though, as a result of the president’s decision to delay enforcement for six months.

Trump didn’t address DACA publicly on Tuesday, even as his administration killed a program that he originally promised to approach with “great heart.” But he did tweet at Congress to act.

Enacted by former President Barack Obama, DACA applies to children who were brought to the United States illegally before their 16th birthday. To be eligible for the program, applicants have to meet a full list of criteria — including requirements that they currently attend or had finished school and that they had not been convicted of a felony.

In undoing DACA, Sessions and others described the program as “an unconstitutional exercise of authority by the Executive Branch.” A collection of 10 state attorneys general agreed, and they threatened to sue the Trump administration over the matter unless the president announced plans to end DACA by today.

Now, with a six-month delay on enforcement, Sessions said there’s a “time period for Congress to act if it should so choose.”

This article originally appeared on Recode.net.