The move by the 9th Circuit Court of Appeals vacates a ruling by a three-judge panel that would have allowed Trump to deploy troops in the Democratic-run city, part of an ongoing drive by the Republican to send troops to cities run by his political rivals that he claims are plagued by crime.

The 9th Circuit voted late Tuesday to have the case reheard by an 11-judge panel, a decision welcomed by Oregon Attorney General Dan Rayfield.

"This ruling shows the truth matters and that the courts are working to hold this administration accountable," Rayfield said in a statement.

"The Constitution limits the president's power, and Oregon's communities cannot be treated as a training ground for unchecked federal authority," he said.

"The court is sending a clear message: the president cannot send the military into US cities unnecessarily."

Trump has ordered hundreds of National Guard troops to Democratic-led cities claiming they are needed to combat crime and protect federal agents carrying out his sweeping immigration crackdown.

The US president has repeatedly called Portland "war-ravaged" and riddled with violent crime, a description dismissed as "simply untethered to the facts" by a Trump-appointed district court judge who initially blocked the National Guard deployment.

A district court and an appeals court have also blocked the deployment of National Guard troops in Chicago, the United States' third-largest city, and the Trump administration has asked the conservative-dominated Supreme Court to lift the lower court rulings.

Trump's extraordinary domestic use of the National Guard was also challenged by Democratic-ruled California earlier this year after the Republican president sent troops to Los Angeles to quell protests sparked by the rounding up of undocumented migrants.

A district court judge ruled it unlawful but an appeals court panel allowed the Los Angeles deployment to proceed.

National Guard troops have also been sent to Memphis, Tennessee, and the US capital, Washington.