Originally Published: 28 SEP 21 22:21 ET

By Paul LeBlanc, CNN

(CNN) -- Florida Republican Gov. Ron DeSantis on Tuesday announced a new lawsuit against the Biden administration over its so-called catch and release immigration policy.

The Department of Homeland Security, Customs and Border Protection, and Immigration and Customs Enforcement are among the defendants named in the complaint.

The lawsuit, while unlikely to bring any swift change to the federal government's border policy, adds to DeSantis' hardline immigration messaging as he looks to position himself as opposite of President Joe Biden on the national political stage on key issues from immigration to the Covid-19 pandemic.

"We are in a situation where we have a disaster on the southern border. That's been apparent for many, many months," DeSantis told reporters at a news conference Tuesday, during which he outlined steps he is taking to counter the White House on issues related to immigration.

Tuesday's lawsuit, filed by Florida Republican Attorney General Ashley Moody in Pensacola, Florida, federal court, claims that -- under "catch and release" -- migrants who are "illegally released" by the Biden administration are "arriving or will arrive in Florida, harming the State's quasi-sovereign interests and forcing it to incur millions of dollars in expenses."

As a result, the lawsuit in part seeks to deem unlawful both the release of undocumented immigrants subject to mandatory detention and the paroling of undocumented immigrants "without engaging in case-by-case adjudication or abiding by the other limits on that authority." The complaint also challenges what it characterizes as a failure "to serve charging documents or initiate removal proceedings" against "plainly inadmissible" undocumented immigrants being released into the US.

"Catch and release" refers to the practice of releasing some undocumented immigrants deemed not to be flight risks and not dangerous on their own recognizance or with monitoring technology following arrest. Many undocumented immigrants end up living in the US for years because of a deeply backlogged immigration court system.

The Department of Homeland Security did not respond to CNN's request for comment. The White House referred CNN to the Justice Department, which did not respond to CNN's request for comment.

Jesse Bless, the director of federal litigation at the American Immigration Lawyers Association, told CNN on Tuesday that "anytime a state wants to take on the federal government about how it's enforcing federal law -- that is an incredibly hard thing to do."

"There's probably no greater topic or area where it's more of a federal issue than immigration. Who comes in and out of this country is entirely -- it's actually in the Constitution -- I mean, it's totally entrusted to the federal government," Bless continued.

"It's one thing to file a complaint where you just simply have to allege things as fact. And it's entirely another thing to win a final judgment where you actually have to provide evidence. When I read the complaint, I did not see evidence attached to the complaint."

In the administration's effort to distance itself from former President Donald Trump's restrictive immigration agenda and strike a note of compassion, Biden officials have often sent conflicting messages about who's allowed into the US and when. As a result, the border situation remains a political liability for the White House, which is drawing criticism from both the left and the right.

The scope of the challenge came into focus again last month, when US Customs and Border Protection announced the agency had encountered 212,672 people at the US-Mexico border in July, a two-decade high.

The lawsuit also comes after a chaotic scene in Del Rio, Texas -- where the Department of Homeland Security has most recently been conducting regular repatriation flights to Haiti -- exposed deep divisions within Biden's administration and among some of the President's staunchest allies over how to approach the thorny issue of immigration.

On Tuesday, DeSantis also signed an executive order that sets forth how Florida state agencies should approach and enforce a number of policies concerning undocumented immigrants. The governor named Larry Keefe, a former US attorney, as "Public Safety Czar" in order to "ensure the actions directed by this executive order, as well as many other things, are carried out."