President Trump is expected to phase out the Obama-era program that grants work permits to about 800,000 undocumented immigrants brought to the United States as children, but delay its end for six months to give Congress time to pass legislation to replace it, according to multiple people briefed on the president's discussions.

Trump's plan remains fluid and could change, however, and administration officials stressed Sunday evening that the president has not finalized his decision. The White House has scheduled an announcement for Tuesday.

Trump has been wrestling over the future of the Deferred Action for Childhood Arrivals (DACA) program since the start of his presidency, and he has been known to change his mind about difficult policy issues until the moment he makes public a decision.

Politico first reported Sunday evening that Trump had decided to end the DACA program.

Two people briefed on Trump's deliberations and a third person with knowledge of the internal discussions said that the White House is preparing to slowly phase out the program so Congress could pass legislation for an alternative program to help the program's recipients, known as "Dreamers." All of these people spoke on the condition of anonymity because of the sensitivity of the discussions.

Many questions remain about how the policy would be implemented, including how long after Trump's announcement current DACA beneficiaries would have to renew their protected status.

Should Trump move forward with this decision, he would effectively be buying time and punting responsibility to Congress to determine the fate of the Dreamers. There is a consensus view among many of his top advisers that the DACA program, which President Barack Obama created by executive action, would not stand up in a court of law.

Attorney General Jeff Sessions, senior policy adviser Stephen Miller and recently departed chief White House strategist Stephen K. Bannon have advocated a hard-line immigration stance with the president, including ending DACA.

During the campaign, Trump vowed to end DACA immediately. But he has since voiced sympathy for the program's beneficiaries, many of whom immigrated to the United States as young children and have lived here for most of their lives.

"We love the Dreamers," Trump told reporters Friday in the Oval Office. "We think the Dreamers are terrific."

Surrogates for Trump said Sunday that American workers would benefit from an end to the DACA program, which has let undocumented children work and study in the United States without fear of deportation, but congressional Republicans urged the White House to leave the program intact.

Attendees hold an American flag as they sing "God Bless America" at a Deferred Action for Childhood Arrivals (DACA) rally in Wilkes Barre, Pa., on Sept. 3. (Dave Scherbenco/AP)

Trump "wants to do what's fair to the American worker, what's fair to people in this country who are competing for jobs and other benefits," counselor to the president Kellyanne Conway said Sunday on "Fox & Friends." She said the president's decision should be viewed as part of an "entire economic and domestic agenda" that includes an end to sanctuary cities, increased border security and constructing a wall along the southern border.

"He says we have to keep people and poison out of our communities. People who are coming here illegally and competing for those jobs," Conway said.

In an appearance on "Fox News Sunday," Treasury Secretary Steven Mnuchin said he was "less concerned about the economic impact" of ending the DACA program because "we'll make sure that we have plenty of workers in this economy. We want to put more people back to work."

Neither Conway nor Mnuchin specified what Trump will say when he addresses the future of the DACA program Tuesday.

As a candidate, Trump promised to end the program, but he has never acted on that promise. Instead, he has several times expressed sympathy for the plight of DACA recipients — and eschewed signing draft executive orders presented to him that would end the program.