Washington DC - The White House said Wednesday President Donald Trump would not allow "mob rule" after protests against his aggressive immigration raids spread across the US despite a military-backed crackdown in Los Angeles.

Press Secretary Karoline Leavitt also attacked the Democratic governor of California and mayor of Los Angeles, claiming they had "fanned the flames" of the clashes.

"President Trump will never allow mob rule to prevail in America," Leavitt told a briefing at the White House, backed by television screens showing images of burning vehicles and masked rioters.

Politicians Republican representative departs Congress in shock resignation

"The most basic duty of government is to preserve law and order, and this administration embraces that sacred responsibility."

Leavitt's comments echoed Trump's in a speech at the Fort Bragg military base on Tuesday, in which he vowed to "liberate" Los Angeles and branded the protesters "animals."

Trump is in conflict with California authorities who have accused the Republican president of being "dictatorial" and seeking political gain by sending in thousands of troops to break up the protests, which have largely been peaceful.

Pockets of violence – including the burning of self-driving taxis and hurling of stones at police – have triggered a massive response from authorities, who have used tear gas and other less-lethal weapons.

"Governor Gavin Newsom and Mayor Karen Bass shamefully failed to meet their sworn obligations to their citizens," Leavitt responded, accusing Newsom of having "fanned the flames and demonized our brave ICE officers."

The protests erupted last week after Immigration and Customs Enforcement (ICE) officers carried out a series of brutal raids in Los Angeles to back up Trump's hardline immigration policies.

Trump has also called the protesters "paid insurrectionists" – alleging that some of them had professional anti-riot equipment – but the White House did not say who it believed was paying them.

"It's a good question the president is raising, and one we are looking into, about who is funding these insurrectionists," Leavitt said when asked by AFP about the president's comments.