ELWOOD, Illinois — US National Guard troops are positioned outside Chicago and they could be in Memphis by Friday, as the Donald Trump administration pushes ahead with an aggressive policy toward big-city crime, whether local leaders support it or not.

National Guard members from Texas had settled in at an Army Reserve center in Illinois by early Wednesday, despite a lawsuit and vigorous opposition from Democratic elected leaders. Their exact mission was not clear, though the Trump administration has an aggressive immigration enforcement operation in the country's third-largest city, and protesters have frequently rallied at an immigration building outside Chicago in Broadview.

The president has called Chicago a "hell hole" of crime, though police statistics show significant drops in most crimes, including homicides.

In Memphis, Tennessee, police Chief Cerelyn Davis said a small group of commanders was already in the city, planning for the arrival of Guard troops.

Republican Governor Bill Lee has said troops will be deputized by the United States Marshals Service to "play a critical support role" for local law enforcement, though that role has not been precisely defined yet.

Trump's bid to deploy the military on US soil over local opposition has triggered a conflict with blue state governors. Illinois and Chicago are urging a federal judge to stop "Trump's long-declared 'War'" on the state. A court hearing on their lawsuit is scheduled for Thursday. In Oregon, a judge over the weekend blocked the Guard's deployment to Portland.

Illinois Governor JB Pritzker has predicted that National Guard troops from the state would be activated, along with 400 from Texas. He has accused Trump of using troops as "political props" and "pawns", and said he did not get a heads-up from Washington about their deployment.

On Wednesday, Trump called for jailing Pritzker and Chicago Mayor Brandon Johnson.

"Chicago mayor should be in jail for failing to protect ICE officers! Governor Pritzker also!" he posted on his social media platform, referring to US Immigration and Customs Enforcement personnel.

The Associated Press saw military personnel in uniforms with the Texas National Guard patch at the US Army Reserve Center in Elwood, about 90 kilometers southwest of Chicago. Trucks marked Emergency Disaster Services dropped off portable toilets and other supplies. Trailers were set up in rows. Extra fencing was spread across the perimeter.

The nearly 150-year-old Posse Comitatus Act limits the military's role in enforcing domestic laws. However, Trump has said he would be willing to invoke the Insurrection Act, which allows a president to dispatch active duty military in states that are unable to put down an insurrection or are defying federal law.

'Extremely dangerous'

Randy Manner, a retired Army major general who served as acting vice-chief of the National Guard Bureau, said using the Insurrection Act in the way Trump appears to be contemplating has no real precedent.

"It's an extremely dangerous slope, because it essentially says the president can just do about whatever he chooses," said Manner, who served under both Republican and Democratic administrations before retiring in 2012.

The Federal Aviation Administration ordered flight restrictions over the Army Reserve Center for security reasons until Dec 6.

Since starting his second term in January, Trump has sent or talked about sending troops to 10 cities, including Baltimore, the District of Columbia, New Orleans, and the California cities of Oakland, San Francisco and Los Angeles.

Most violent crime around the US has declined in recent years. In Chicago, homicides were down 31 percent to 278 through August, police data showed. Portland's homicides from January through June decreased by 51 percent year-on-year to 17.

In Portland, months of nightly protests at a US Immigration and Customs Enforcement facility continued on Tuesday night. In June, police declared a riot, and there have been smaller clashes since then.

Agencies Via Xinhua