U.S. Defence Secretary Pete Hegseth has ordered the removal of half of the 4,000 National Guard troops who had been sent to Los Angeles to protect federal property and personnel during a spate of protests last month, the Pentagon said on Tuesday.

Pentagon spokesperson Sean Parnell said the decision was due to the success of the mission.

"Thanks to our troops who stepped up to answer the call, the lawlessness in Los Angeles is subsiding," Parnell said in a statement.

U.S. President Donald Trump deployed the troops to Los Angeles in June, against the wishes of Democratic Gov. Gavin Newsom, to quell protests triggered by immigration raids on workplaces by Immigration and Customs Enforcement (ICE) agents.

He also sent about 700 marines.

Despite legal challenges, a U.S. appeals court let Trump retain control of California's National Guard.

But his decision to send troops into Los Angeles prompted a national debate about the use of the military on U.S. soil and inflamed political tension in the country's second most-populous city. The Pentagon has defended the deployment, saying safeguarding ICE agents ensures they can do their jobs.

Even after the withdrawal of those military personnel from Los Angeles, 2,000 National Guard troops will remain in the city along with the roughly 700 marines.

Los Angeles Mayor Karen Bass, who has complained that military force was unnecessary and damaging to the local economy, said popular opposition contributed to the withdrawal.

Protesters regularly appear at immigration raids in the Los Angeles area, demonstrating their opposition to the government's display of force.

"This happened because the people of Los Angeles stood united and stood strong. We organized peaceful protests, we came together at rallies, we took the Trump administration to court — all of this led to today's retreat," Bass said.

She referred to a lawsuit the city joined that led to an order from a federal judge barring immigration officers from detaining people based solely on their race or for speaking Spanish.

The troops in Los Angeles are authorized to detain people who pose a threat to federal personnel or property, but only until police can arrest them. Military officials are not allowed to carry out arrests themselves.

Trump has vowed to deport millions of people in the country illegally and has executed raids at work sites including farms that were largely exempted from enforcement during his first term. The administration has faced dozens of lawsuits across the country challenging its tactics.