A US judge blocked President Donald Trump's administration on Tuesday from ending a programme that shielded from deportation children brought to the United States illegally by their parents.

Trump decided in September to rescind the Deferred Action for Childhood Arrivals programme, or DACA. 

US District Judge William Alsup ruled in San Francisco that the programme must remain in place while litigation over Trump's decision unfolds.

The ruling came as Trump and US congressional leaders negotiated broad immigration reforms.

Responding to the court's decision President Trump blasted the federal court system as "broken and unfair." 

DACA supports 0.8 million young people

The DACA programme has provided protection from deportation and the right to work legally to nearly 800,000 young people since it was authorised by President Barack Obama in 2012.

Several states, organisations and individuals have filed lawsuits seeking to protect DACA recipients, who are known as Dreamers.

Alsup said in his ruling the federal government did not have to process new applications from people who had never before received protection under the programme.

Representatives for the White House, the Department of Justice and the Department of Homeland Security could not be reached immediately for comment.

Trump ran on a hardline immigration platform during the 2016 presidential election, promising to end DACA and strengthen border protections to increase jobs for US workers.