US President Donald Trump on Wednesday called for the jailing of Chicago Mayor Brandon Johnson and Governor JB Pritzker, accusing the two Democratic lawmakers of failing to protect members of the immigration enforcement agency (ICE).

“The mayor of Chicago should be in jail for failing to protect ICE agents! So should Governor Pritzker!” he wrote on his Truth Social network.

Two hundred National Guardsmen have arrived near Chicago, a US defense official said Tuesday, after the president described the large northern city as a "war zone."

Donald Trump authorized the deployment of 700 National Guardsmen this weekend, but the Democratic opposition challenged the legality of the decree in court, accusing the billionaire of "punishing his political enemies."

She claims the Trump administration is using protests outside an ICE facility in suburban Chicago as a "pretext" to justify sending in troops.

The federal judge in charge of the case has scheduled a hearing for Thursday.

This weekend, a judge temporarily blocked a similar deployment in Portland, another Democratic city in the northwest. She argued that there was "no insurrection in Portland, nor a threat to national security," contrary to the Trump administration's claims.

Donald Trump has been targeting Chicago for weeks and has raised the possibility of invoking the Insurrection Act, a compilation of laws from the 18th and 19th centuries. It allows for the declaration of a state of emergency authorizing the use of armed forces against American citizens, a practice that is prohibited in principle.

The president has already deployed National Guard troops to the Democratic cities of Los Angeles, Washington, and Memphis (southern), each time against the advice of local authorities.