President Donald Trump appeared to throw a lifeline Tuesday night to nearly 1 million undocumented immigrants, just hours after signaling his administration planned to deport them.

Trump took to Twitter Tuesday night and appeared to contradict himself and Attorney General Jeff Sessions by signaling he might sign an order providing protection to those 800,000 people if Congress fails to pass a bill addressing their presence in the U.S.

Trump and Sessions earlier in the day argued they were terminating former President Barack Obama’s DACA immigration program mostly because he created it via executive order.

“The policy was implemented unilaterally, to great controversy and legal concern, after Congress rejected legislative proposals to extend similar benefits … on numerous occasions to this same group of illegal aliens,” Sessions said at a morning press conference. “Such an open-ended circumvention of immigration laws was an unconstitutional exercise of authority by the executive branch.”

[Analysis: Trump Hits Congress With Immigration Quandary]

Trump followed that with a similar conclusion in a written statement defending his decision soon after.

“The legislative branch, not the executive branch, writes these laws – this is the bedrock of our Constitutional system, which I took a solemn oath to preserve, protect, and defend,” Trump said.

“The attorney general of the United States, the attorneys general of many states, and virtually all other top legal experts have advised that the program is unlawful and unconstitutional and cannot be successfully defended in court,” Trump concluded.

But nine hours later, Trump fired off a major contradiction by signaling his interest in signing an order similar to or much like the 2012 Obama order creating the Deferred Action for Childhood Arrivals program, known as DACA.

The tweet noted he has built into his DACA-killing directive a six-month wind-down period during which he wants Congress to pass a bill address the so-called “Dreamers,” meaning undocumented individuals who had been protected by Obama’s order.

[White House Adds Sweeping Immigration Bill to Lawmakers’ Agenda]

To be sure, the crux of the Sessions-Trump justification was that Obama’s order was illegal — Sessions even said he concluded it would not have held up in court as several state attorneys general were gunning to take it down. And Trump’s top spokeswoman, Sarah Huckabee Sanders, on Tuesday called Trump’s a decision mostly a “legal” matter.

Yet, the president tweeted that if Congress fails to pass an immigration bill addressing the Dreamers in that six-month period, he will “revisit” the matter.

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!

— Donald J. Trump (@realDonaldTrump) September 6, 2017

That appears to contradict his own rationale for canceling the Obama program because, based on his own reasoning, that action would circumvent Congress and the Constitution’s separation of powers provisions.