The Obama era programme protects around 800,000 people from deportation
Barack Obama has described the Trump administration's decision to end the so-called 'Dreamers' programme for young undocumented immigrants in the US as "cruel".
The scheme - called Deferred Action for Childhood Arrivals (DACA) - was introduced by the Obama administration in 2012.
It protects around 800,000 people who entered the US illegally as children from deportation for a renewable two-year period, while allowing them to work.
DACA also provides those in the scheme with access to benefits such as social security.
Announcing the decision to end the programme today, Attorney General Jeff Sessions said the programme will be wound down - but added that the process will allow time for the US Congress to come up with a replacement legislation 'should it so choose'.
It means those affected will not be immediately impacted by the decision to end the programme.
The New York Times reports the scheme was due to expire on March 5th 2018.
President Trump - who has repeatedly vowed to crackdown on immigration - had earlier tweeted that Congress should prepare to 'do your job' over the scheme:
Congress, get ready to do your job - DACA!— Donald J. Trump (@realDonaldTrump) September 5, 2017
Mr Sessions in a statement accused the Obama of acting 'unconstitutionally' in introducing DACA.
He argued: "The executive branch, through DACA, deliberately sought to achieve what the legislative branch specifically refused to authorise on multiple occasions. Such an open-ended circumvention of immigration laws was an unconstitutional exercise of authority by the Executive Branch.
"The effect of this unilateral executive amnesty, among other things, contributed to a surge of unaccompanied minors on the southern border that yielded terrible humanitarian consequences. It also denied jobs to hundreds of thousands of Americans by allowing those same jobs to go to illegal aliens."
In comments to US reporters after the announcement, Donald Trump said he was optimistic Congress would now act.
Speaking about those afforded protection by DACA, he observed: "I have a great heart for the folks we're talking about... a great love for them. 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."
Pres. Trump on his administration rescinding DACA: "I have a love for these people and hopefully now Congress will be able to help them." pic.twitter.com/CLMHcLdJyH— ABC News (@ABC) September 5, 2017
There had been widespread speculation about the fate of DACA in recent days, amid mounting speculation that President Trump was planning to scrap it.
Barack Obama responded to today's news in a Facebook post, saying the decision was '"cruel".
He wrote: "To target these young people is wrong – because they have done nothing wrong. It is self-defeating – because they want to start new businesses, staff our labs, serve in our military, and otherwise contribute to the country we love. And it is cruel.
"Let’s be clear: the action taken today isn’t required legally. It’s a political decision, and a moral question."
He added that the White House "has shifted its responsibility for these young people to Congress".
The scheme, or at least the principle behind the scheme, has drawn some high-profile supporters - including Apple boss Tim Cook.
250 of my Apple coworkers are #Dreamers. I stand with them. They deserve our respect as equals and a solution rooted in American values.— Tim Cook (@tim_cook) September 3, 2017
Facebook's Mark Zuckerberg has also come out in support of DACA.
In a Facebook post, he described the decision as a 'sad day' for the US, arguing: "It is particularly cruel to offer young people the American Dream, encourage them to come out of the shadows and trust our government, and then punish them for it."
Hillary Clinton said "we've got to fight with everything we've got" to defend the programme, while Democratic politicians such as Elizabeth Warren have also spoken out in favour of making the scheme permanent: