The US Justice Department has asked the Supreme Court to quickly overturn a lower court ruling blocking President Donald Trump's move to end a program that protects hundreds of thousands of immigrants brought to the United States illegally as children.
Solicitor-General Noel Francisco asked the high court to rule on the case before its current term ends in June.
In September, Trump rescinded, effective in March, the program known as DACA, put in place in 2012 by his Democratic predecessor, Barack Obama.
Trump asked the Republican-controlled Congress to come up with a legislative fix, which it has not yet done.
A variety of Democratic state attorneys general, organisations and individuals challenged Trump's action in multiple federal courts.
The administration is challenging a January 9 decision by US District Judge William Alsup, who ruled that DACA must remain in place while the litigation is resolved.
A decision could take more than a year if the court takes up the case but declines to speed up resolution of it issuing a ruling in its current term.
About 800,000 young, mostly Hispanic adults dubbed "Dreamers," have been protected from deportation and allowed to work legally in the United States since the program was implemented.
