President Trump on Monday announced illegal immigrants will be “given” to Sanctuary Cities and States, pending official decisions from the Department of Homeland Security.

“Those Illegal Immigrants who can no longer be legally held (Congress must fix the laws and loopholes) will be, subject to Homeland Security, given to Sanctuary Cities and States!” Trump tweeted Monday.

The president’s announcement comes after reports revealed last week that the administration had floated releasing detained immigrants into sanctuary cities twice over the last six months.

Last week, Trump all but confirmed the reports and stated that the administration was still "giving strong considerations" to the measure. His Monday tweet seemingly signaled the administration would adopt the policy.

The proposal was apparently rejected both times it came up--in November and in February-- by administration immigration agencies. It is unclear, at this point, whether immigration agencies would now support the proposal with new leadership in place.

A spokesperson for DHS did not immediately respond to Fox News’ request for comment.

The president's new plan comes amid a shake-up at the Department of Homeland Security. Last week, DHS Secretary Kirstjen Nielsen resigned, and the president replaced her with Kevin McAleenan as acting DHS secretary, who was serving as Customs and Border Protection commissioner.

Nielsen’s resignation last Sunday came amid an influx of migrants at the U.S.-Mexico border. Nielsen was reportedly frustrated with the difficulty of getting other departments to help deal with the growing number of families crossing the border. But administration officials told Fox News that McAleenan best fits Trump’s requirement of being the “toughest cop” on the frontier and that Nielsen had been viewed as resistant to some of the immigration measures pushed by the president and his aides.

Also last week, Randolph "Tex" Alles, stepped down from his post as head of the Secret Service; DHS Acting Deputy Secretary Claire Grady also resigned; and last Wednesday, Nielsen announced that ICE Acting Director Ron Vitiello would be stepping down by the end of the week.

HOUSE DEMOCRATS DEMAND DOCS ON TRUMP ADMINISTRATION'S 'BIZARRE AND UNLAWFUL' PROPOSAL TO RELEASE MIGRANTS IN SANCTUARY CITIES

The proposal, first reported by The Washington Post, was seen as a political move by the president, who has repeatedly blasted sanctuary cities, which are cities, typically run by Democrats, where local authorities refuse to cooperate with federal immigration agencies.

“Due to the fact that Democrats are unwilling to change our very dangerous immigration laws, we are indeed, as reported, giving strong considerations to placing Illegal Immigrants in Sanctuary Cities only,” Trump tweeted last week, suggesting that “the Radical Left” should be “happy” with the idea.

Democrats fumed over the proposal last week, and on Monday, House Judiciary Committee Chairman Jerrold Nadler, D-N.Y.; House Oversight Committee Chairman Elijah Cummings, D-Md., and House Homeland Security Chairman Bennie Thompson, D-Miss., penned a letter to DHS and the White House Monday requesting emails, and other communications between administration officials related to the proposal.

“We are deeply troubled by multiple reports, recently confirmed by the President, that the Trump Administration is considering releasing detained immigrants into congressional districts represented by Democrats in a bizarre and unlawful attempt to score political points,” the chairmen wrote.

“Not only does the Administration lack the legal authority to transfer detainees in this manner, it is shocking that the President and senior Administration officials are even considering manipulating release decisions for purely political reasons,” they continued.

TRUMP DOUBLES DOWN ON PLAN TO SHIP MIGRANTS TO SANCTUARY CITIES, SAYS 'RADICAL LEFT' SHOULD BE 'HAPPY'

Last week, House Speaker Nancy Pelosi’s office released a statement blasting the idea. Pelosi’s, D-Calif., district—San Francisco, specifically—was among the sanctuary cities to which the administration was considering sending detainees.

“The extent of this Administration’s cynicism and cruelty cannot be overstated,” Pelosi’s spokeswoman Ashley Etienne said in a statement Friday. “Using human beings—including little children—as pawns in their warped game to perpetuate fear and demonize immigrants is despicable, and in some cases, criminal.”

She added: “The American people have resoundingly rejected this Administration’s toxic anti-immigrant policies, and Democrats will continue to advance immigration policies that keep us safe and honor our values.”

Fox News' Kristin Brown, Matt Leach, and The Associated Press contributed to this report.