"....The Radical Left always seems to have an Open Borders, Open Arms policy – so this should make them very happy!" the president wrote in a second tweet.
Trump's announcement is a near-total reversal by the president of the official position his White House has taken so far.
In a statement Thursday to reporters, a Homeland Security Department spokesman said the plan "was a suggestion that was floated and rejected, which ended any further discussion."
A former DHS official, discussing the White House's thinking, told NBC News that the plan was dropped when it was deemed "so illegal."
In a statement following the president's tweet, a White House spokesperson chided Democrats for opposing the plan and said they "should be working with the Administration."
"Democrats say we must have open borders and that illegal immigrants have a right to be in this country at all costs, so they should be working with the Administration to find the best ways to transport those illegal aliens that are already set for release, into communities in their states and districts," the spokesman, Hogan Gidley, said.
Later Friday, during an event related to 5G deployment, the president said that "we will bring them to sanctuary city areas and let that particular area take care of it, whether it's a state, or whatever that might be."
"We can give them an unlimited supply, and let's see if they're so happy," Trump said.
According to The Washington Post, the plan was geared toward delivering political retribution to Democrats including House Speaker Nancy Pelosi, whose San Francisco district was discussed as a target.
Pelosi on Friday told reporters that the plan was "just another notion that is unworthy of the presidency of the United States and disrespectful, the challenges we face as a country, as a people to address who we are — a nation of immigrants."