The message is in a document obtained by ABC News that was provided to members of Congress after the Trump administration announced its decision to end DACA, which defers deportation for so-called Dreamers, or unauthorized immigrants who arrived in the U.S. as children.
Two congressional sources and one administration official confirmed the authenticity of the document, titled "Talking Points — DACA Rescission."
One senior U.S. official familiar with the document said the administration stands by that point as written.
"Once DACA expires, they are in this country illegally," the official said. "And once that expires, we expect them to no longer remain in our country illegally."
The White House said earlier Tuesday that Dreamers are "not a targeted priority" of immigration officials.
White House press secretary Sarah Sanders would not definitively answer when asked on Tuesday if those protected by the policy could face deportation after the program's six month phase-out.
"We'd like to have confidence that Congress will actually do their job," she said. "We're going to ask that they do that and that they allow us to work with them and be part of that process."
But Tuesday night, Trump tweeted, "Congress now has 6 months to legalize DACA (something the Obama Administration was unable to do). If they can't, I will revisit this issue!"