President Trump, as early as Friday, is expected to announce plans to end the Obama administration program that gave a deportation reprieve to hundreds of thousands of young illegal immigrants, a senior administration official told Fox News.

Trump promised to terminate the Deferred Action for Childhood Arrivals program, or DACA, during the presidential campaign -- but since taking office had left the door open to preserving parts of it.

According to the official, Trump is expected to announce the program's end but will allow so-called “dreamers” currently in the program to stay in the U.S. until their work permits expire – which, for some, could be as long as two years.

The White House suggested Thursday afternoon, though, that Trump has yet to give the final sign-off. White House Press Secretary Sarah Sanders told reporters at the daily briefing the program is still “under review.”

“A final decision on that front has not been made, and when it is, we will certainly inform everybody in this room,” she said.

The program was formed through executive order by then-President Barack Obama in 2012 and allows for certain people who came to the U.S. illegally as minors to be protected from immediate deportation.

Recipients are able to request “consideration of deferred action” for a period of two years which is subject to renewal.

WHAT IS DACA AND WHY WOULD TRUMP DISMANTLE IT?

The plan to allow DACA to lapse already has buy-in from conservative groups that want the president to end the program.

“Our position has been that President Trump should allow DACA to lapse,” Ira Mehlman from the Federation for American Immigration Reform told Fox News. “As people's two-year deferments and work authorization expire they should not be renewed.”

In an interview with ABC News this spring, the president earlier suggested he might not entirely do away with DACA.

“They shouldn’t be very worried,” Trump said of the young people in the program. “I do have a big heart.”

Daniel Garza, president of the Libre Initiative, told Fox News that DACA offers a "reprieve from a life of uncertainty for innocent kids who didn't break the law."

"It's rather disappointing to think they could return to a state of anxiety and fear," Garza said.

He called on Congress to pass a "permanent resolution for these innocent kids."

Democrats on Thursday expressed opposition to the move, referencing the president’s past comments.

“If he ends DACA, Trump would betray #DREAMers he said he'd treat w/ ‘great heart.’ These incredible young people make our country stronger,” tweeted Virginia Sen. Tim Kaine, the 2016 Democratic vice presidential nominee.

Fox News’ John Roberts, Kaitlyn Schallhorn and Alex Pappas contributed to this report.