WASHINGTON - Chicago, often referred to as the "second city" of the United States, could be the next metropolis to see the deployment of National Guard troops as part of US President Donald Trump's efforts to fight crime.

Sometimes even labelled as a "military conflict zone," Chicago has many times topped the list of US cities with the most gun violence.

According to News Nation, a US cable news network, the Trump administration has "been working on plans to deploy thousands of National Guard members to Chicago."

"The Guard mobilization in Chicago, if it does come to pass, would resemble the military presence Trump ordered in Washington, DC to combat crime and homelessness," said the report.

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National Guard troops have now been authorized to carry firearms in Washington, DC, according to the Defense Department.

If troops are deployed to Chicago, the Pentagon could send at least 3,000 members as soon as September, the Washington Post reported.

Trump has already suggested that Chicago could be the next Democrat-controlled city for what he described as a crackdown on lawlessness. He told reporters at the White House on Friday that Chicago could be the next city the federal government targets in its crime crackdown, following several days of action in Washington, DC.

Trump on Monday signed an executive order directing "additional specific actions" to "further crack down on crime" in the capital area, while signaling nationwide deployment of the National Guard.

The order directs the Secretary of Defense to create a "specialized DC National Guard unit" trained to ensure public safety and order in the city when necessary, and "ensure state National Guards are similarly trained and ready to assist in quelling civil disturbances nationwide."

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This occurs as Republicans have blasted Democrats for allowing a progressive minority to steer the entire party.

Republicans -- including Trump -- claim this has been disastrous for dozens of US cities, where many district attorneys' campaigns have been funded by progressives who believe that criminals should receive light punishments.

White House border czar Tom Homan on the weekend told News Nation that "Chicago was indeed a possibility for troop deployments, as he discussed a separate plan to have the National Guard assist officers of US Immigration and Customs Enforcement across 19 states."

At the same time, there is a growing pushback to Trump's possible plans to deploy troops to Chicago, with Mayor Brandon Johnson criticizing communication from the White House on the issue as being "notably absent," ABC 7 reported.

Many critics of Trump's National Guard deployment in DC note statistics showing crime has gone down in recent years, and argue that troop deployment is unnecessary. Some believe Trump is making some sort of power grab, or trying to punish the leadership of Democratic-led cities.

Brookings Institution Senior Fellow Darrell West told Xinhua, "Local officials in those places already have expressed anger at these plans and say they are illegal. There likely will be lawsuits saying the president is overstepping his authority and seeking to prevent deployment. Local leaders say his supposed attack on crime is hypocritical because his recent budget bill cut funding for local police."

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Regarding the possible lawsuits, Clay Ramsay, a researcher at the Center for International and Security Studies at the University of Maryland, said, "Trump can legally federalize the National Guard. Courts may say after the fact that how it was done was illegal, and this may happen in a pending California case. If so, Trump can turn to the Insurrection Act of 1807."

The Insurrection Act of 1807 is a US federal law that grants the president authority to deploy the military and National Guard domestically in specific situations, such as to restore public order in cases of rebellion, unrest or obstruction of federal law.

Meanwhile, the Conservative group "Chicago Flips Red" said that despite police statistics showing a drop in crime, many Chicagoans feel unsafe, ABC 7 reported.

Many conservatives, as well as ordinary residents of cities such as New York, say the statistics do not take into consideration numerous factors, such as crazed homeless people screaming in the face of commuters on the subway daily and the scores of drug addicts roaming the subways, where they defecate and urinate.