A divided US appeals court ruled on Monday that Donald Trump can send National Guard troops into Portland, Oregon, despite objections by the leaders of the city and state, giving the Republican president an important legal victory as he dispatches military forces to a growing number of Democratic-led locales.

A three-judge panel of the 9th US Circuit Court of Appeals granted the Justice Department's request to put on hold a judge's order that had blocked the deployment while a legal challenge to Trump's action plays out.

The court said that sending in the National Guard was an appropriate response to protesters, who had damaged a federal building and threatened US Immigration and Customs Enforcement officers.

The unsigned majority opinion was joined by Circuit Judge Bridget Bade and Circuit Judge Ryan Nelson, who were both appointed by Trump in his first term. Nelson also wrote a concurring opinion saying courts have no ability to even review the president's decision to send troops.