Texas Gov. Greg Abbott speaks during a border security briefing with sheriffs from border communities at the Texas State Capitol on July 10 in Austin, Texas.
CNN  — 

Attorney General Merrick Garland threatened legal action against Texas Gov. Greg Abbott’s executive order targeting migrants in a Thursday letter, calling it “both dangerous and unlawful” and urging the governor to immediately rescind it.

On Wednesday, Abbott issued an executive order restricting ground transportation of migrants “who pose a risk of carrying Covid-19 into Texas communities” and directing Texas Department of Public Safety to stop any vehicle it finds suspicious, marking the governor’s latest attack against the administration’s immigration policies.

CNN first reported that the Biden administration was considering challenging the move and that the Department of Homeland Security is also reviewing it.

Abbott, a Republican who’s up for re-election in 2022, has repeatedly tried to link a rise of Covid-19 cases to migration, though he’s stalled efforts by the Biden administration to provide federal funds for Covid-19 tests for migrants released from custody.

In his letter, Garland said the order violates federal law “in numerous respects” and warned of its implications, saying that Texas has no authority to interfere with US immigration enforcement.

“The Order would jeopardize the health and safety of noncitizens in federal government custody, federal law enforcement personnel and their families, and our communities. Among other harms, the Order would exacerbate and prolong overcrowding in facilities and shelters and obstruct the federal government’s arrangements with state, local, and nongovernmental partners to ensure that released individuals are transported for appropriate COVID-19 testing to address public health concerns,” the letter reads.

“Additionally, because federal law requires individuals processed for release to appear before immigration courts or report to U.S. Immigration and Customs Enforcement offices throughout the country, the Order directly interferes with the implementation of federal immigration law,” it continues.

The Department of Homeland Security also sent Wednesday’s order to its attorneys to get their assessment, according to Democratic Rep. Henry Cuellar of Texas, who spoke to department officials.

In a statement Thursday afternoon, Abbott said he would fight any effort from the Justice Department.

“(T)he Biden Administration is jeopardizing the health and safety of Texans on a daily basis by refusing to follow the law,” Abbott said. “And it’s not just Texans; these irresponsible policies and actions by the Biden Administration are endangering the lives of many Americans as well as the unlawful immigrants themselves. I will take every available step consistent with the law to fulfill my duty to protect the health and safety of all Texans.”

Federal officials say Abbott’s actions risk worsening the situation along the US southern border despite his pronouncements that the directives will strengthen security.

The executive order doesn’t apply to federal, state or local law enforcement, but it could put US Customs and Border Protection in a bind because the agency relies in part on non-governmental organizations to assist in transporting migrants to their next destination, a CBP official told CNN. Losing support from NGOs could take agents away from processing to provide transport, the official added.

“This is intentionally trying to mess things up,” the CBP official said.

Democratic Rep. Vicente Gonzalez of Texas called the order “very disruptive.”

“I think it’s a violation of many people’s civil rights. I think it’s going to lead to racial profiling,” Gonzalez told CNN, referring to Abbott. “This executive order wasn’t very thoughtful. I don’t think he’s really thinking about the end game of where this is going to take us.”

Gonzalez said he’s spoken with House Speaker Nancy Pelosi about the order and is organizing a meeting with Homeland Security Secretary Alejandro Mayorkas about next steps.

Ongoing federal disputes with Texas

It’s not the first time Abbott’s directives have threatened to disrupt federal operations. Earlier this year, Abbott ordered state health officials to stop licensing child-care facilities that house migrant children operated by the Office of Refugee Resettlement, the agency under the Department of Health and Human Services tasked with the care of migrant children. HHS responded by sending a letter threatening legal action.

Immigrant advocates and legal observers have also questioned the legality of Abbott’s directives and cast his actions as trying to score political points. Aaron Reichlin-Melnick, policy counsel at the American Immigration Council, called Wednesday’s order “unconstitutional on its face.”

“It also strongly increases the risk of unconstitutional racial profiling by calling on Texas DPS to pull over any vehicle that they have reasonable suspicion is transporting migrants,” Reichlin-Melnick said, noting that the order could affect ongoing efforts between the administration and organizations.

“That could severely disrupt the Biden administration’s effort to create a public and private partnership to ensure migrants released by government custody are not simply dropped off at the bus station with no idea where to go,” he added.

Nongovernmental organizations often help transport migrants who are released from company, using companies, like Greyhound, to get people around. Asked about the Texas order, Greyhound said in a statement that the company “complies with all federal and state laws.”

While rolling out its immigration agenda, the Biden administration has also contended with a high number of arrests at the US southern border. In June, US Border Patrol apprehended 178,416 migrants at the US-Mexico border, some of whom were repeat crossers, according to the latest available CBP data.

In the latest indication of the administration’s wariness over migrants, including those seeking asylum, journeying to the US southern border, officials scratched plans to wind down a Trump-era border policy linked to the pandemic at the end of this month, angering advocates who say it puts migrants in harm’s way. This week, the administration also announced plans to speed up deportations for some migrant families who cross the US-Mexico border.

This story has been updated with a statement from Gov. Abbott.

CNN’s Tierney Sneed and Evan Perez contributed to this report.