WASHINGTON — President Donald Trump said late Tuesday that he will “revisit” a program protecting young immigrants brought into the country illegally as children if Congress doesn’t act — hours after his administration announced it was phasing out the program.

“Congress now has 6 months to legalize DACA (something the Obama Administration was unable to do),” the president tweeted shortly before 8 p.m. Chicago times. “If they can’t, I will revisit this issue!”

Trump gave no indication what that means.

Trump’s Attorney General Jeff Sessions announced earlier Tuesday that the administration was phasing out President Barack Obama’s Deferred Action for Childhood Arrivals, or DACA, program, but gave Congress six months to come up with an alternative before ending it completely.

Trump had tweeted earlier in the day that he was looking forward to working with Republicans and Democrats in Congress “to address immigration reform in a way that puts hardworking citizens of our country 1st.”

In his only public appearance discussing the matter on Tuesday, Trump said he has a “great love” for the young immigrants protected by the DACA program and looked forward to working with Congress to “help them and do it properly.”

“Well, I have a great heart for the folks we’re talking about — a great love for them,” the president told reporters questioning him before a meeting with administration officials and congressional leaders. “And people think in terms of children, but they’re really young adults.  I have a love for these people, and hopefully now Congress will be able to help them and do it properly.

“And I can tell you, in speaking to members of Congress, they want to be able to do something and do it right.  And really, we have no choice.  We have to be able to do something, and I think it’s going to work out very well.  And long-term, it’s going to be the right solution.”

Trump’s decision was met with shock, anger and a sense of betrayal by its beneficiaries, often called “Dreamers.”

Demonstrations broke out in Chicago, New York City, where police handcuffed and removed over a dozen immigration activists who briefly blocked Trump Tower, and in other cities, including Salt Lake City, Denver, Los Angeles and Portland, Oregon.