The US Supreme Court has ruled sweeping immigration raids in Los Angeles can continue for now, lifting a federal judge's order that had barred agents from making stops without reasonable suspicion.

The Monday ruling is a win for President Donald Trump, who has vowed to conduct record-level deportations of migrants in the country illegally.

The 6-3 decision of the conservative-majority court allows agents to stop suspects based solely on their race, language, or job, while a legal challenge to the recent immigration sweeps in LA works its way through the courts.

The liberal justices dissented, saying the decision puts constitutional freedoms at risk.

Conservative Justice Brett Kavanaugh wrote in Monday's decision that the lower court's restraining order went too far in restricting how Immigration and Customs Enforcement (ICE) agents could carry out stops or questioning of suspected unlawful migrants.

To be clear, apparent ethnicity alone cannot furnish reasonable suspicion, he wrote. However, it can be a 'relevant factor' when considered along with other salient factors.

The Supreme Court's three liberal justices issued a strong dissent penned by Justice Sonia Sotomayor, who wrote that countless people in the Los Angeles area have been grabbed, thrown to the ground, and handcuffed simply because of their looks, their accents, and the fact they make a living by doing manual labor. Sotomayor added, Today, the Court needlessly subjects countless more to these exact same indignities.

The ruling drew criticism from Los Angeles Mayor Karen Bass, a Democrat, who stated, Today's ruling is not only dangerous - it's un-American and threatens the fabric of personal freedom in the United States of America.

The decision nullifies an order by US District Judge Maame E Frimpong in Los Angeles, who had indicated that there exists a mountain of evidence showing that the raids were violating the US Constitution.

The temporary restraining order was issued following a legal challenge from immigration advocacy groups, who argued the raids involved indiscriminate stopping of individuals and denial of access to legal representation.

The Supreme Court's decision arrives as the Trump administration seeks to intensify law enforcement in various cities. National Guard troops have already been deployed to several locations, in light of ongoing civil unrest and concerns surrounding crime.