A federal judge on Wednesday blocked President Donald Trump's deployment of National Guard troops in Los Angeles and ordered the troops be returned to the state governor's control.

In June, Trump sent thousands of National Guard troops to the California city in the wake of protests over his administration ramping up immigration raids in Los Angeles.

US District Judge Charles Breyer said the Trump administration had not proven that that the city's protests against immigration justified taking federal control of the state's National Guard.

The Trump administration still has control over 300 California National Guard troops six months after they were federalised, Judge Breyer said.

Breyer also denied the Trump administration's argument that the courts should not weigh in on a president taking control of state National Guard troops during an emergency.

"The Founders designed our government to be a system of checks and balances," Judge Breyer wrote in his ruling. "Defendants, however, make clear that the only check they want is a blank one."

Judge Breyer said his order would not go into effect until 15 December, giving the Trump administration time to make its expected appeal to a higher court.

"President Trump exercised his lawful authority to deploy National Guard troops to support federal officers and assets following violent riots," said White House spokeswoman Abigail Jackson in a statement to the BBC, adding "we look forward to ultimate victory on the issue."

This year, Trump has sent National Guard troops to several cities, including Portland, Oregon, and Washington DC, where the deployments have also been contested in courts and, in some cases, blocked by judges.

California Governor Gavin Newsom sued soon after Trump first deployed thousands of troops in June, but a court of appeals sided with the administration, saying the protests in Los Angeles justified Trump's federalisation of the National Guard.

Newsom filed a new legal challenge in November, arguing the protests in the city had largely subsided and therefore the troops were no longer necessary.

In a hearing in the case on Friday, lawyers for the Trump administration said the troops should stay in LA because federal immigration agents there were still being targeted.

But Judge Breyer seemed to question the need for troops to remain in the city months later.

"I think experience teaches us that crises come and crises go," he said, according to the Associated Press.

In his ruling, Judge Breyer said the Trump administration was "effectively creating a national police force made up of state troops" by sending California's National Guard troops to other states as well.

Judge Breyer previously ruled that the way Trump deployed the National Guard to Los Angeles this summer was illegal.

All 50 US states, the District of Columbia, and several territories have their own contingent of National Guard troops.

President Donald Trump's deployment of the National Guard to several US cities has drawn a round of legal challenges by state and local officials.

Trump has argued that his use of the troops is necessary to quell violence in Democratic-controlled cities, crack down on crime and support his deportation initiatives.