The Trump administration is scrambling to conduct environmental impact reviews of warehouses it plans to convert into immigrant holding facilities, after a flurry of lawsuits claiming the administration sidestepped federal requirements.

The Immigration and Customs Enforcement agency is buying the warehouses to help it increase the rate of deportations, which depends on having enough space to house detainees. The administration currently has about 58,000 immigrants in custody, and fell short of its target to reach 100,000 beds by the end of last year.

But the plan to buy and retrofit commercial warehouses to accommodate tens of thousands more detainees may be delayed after hitting roadblocks, including opposition from residents and officials in the communities where the warehouses are located. Now, states are trying to block the projects by arguing that the Trump administration failed to do environmental reviews required under federal law.

In court filings, ICE officials have argued the warehouse renovations are exempt from reviews required under the National Environmental Policy Act, citing a variety of reasons.

Justice Department officials have voiced concern in recent weeks that the approach could leave the administration vulnerable to legal challenges, internal documents show. Those fears were realized this month when a federal judge in Maryland blocked plans to retrofit a warehouse in the state, citing the lack of an environmental review.

“That Maryland result changed their strategy,” said Jamison E. Colburn, a professor at Pennsylvania State University who focuses on environmental law. The administration’s move to conduct environmental reviews, he said, appeared to be “them biting the bullet in view of a bigger loss if they didn’t.”

Agency officials now have plans to conduct environmental assessments of at least two of the warehouse sites the government has purchased, according to documents obtained by The New York Times. The reviews could take months, according to experts.

So far, the Department of Homeland Security, which houses ICE, has purchased 11 warehouses across the country for about $1 billion.

In the Maryland case, the federal government argued that the project was exempt from a review under the National Environmental Policy Act because it was, among other things, not close to any environmentally sensitive zones and was in an area that had already been built on. In filings in New Jersey and Michigan, the government indicated it would complete the environmental assessments after developing more specific retrofit plans.

So far, legal challenges targeting environmental issues have been filed against warehouse projects in New Jersey, Michigan, Maryland and Arizona.

In a statement, homeland security officials said the agency had complied with federal laws and accused liberals of backing the effort to compel environmental reviews to slow down the Trump administration’s deportation campaign.

The warehouse plan is also intended to help scale back the government’s reliance on private contractors and state entities. Owning more of the detention facilities would allow the government to have more control of the space. But a senior U.S. official, who was not authorized to speak publicly on the matter, told The Times that the new homeland security secretary, Markwayne Mullin, had expressed skepticism about purchasing more warehouses.

Todd Lyons, the acting head of the immigration agency, told the House Appropriations Committee this month that Mr. Mullin was still studying ICE’s warehouse plans.

“He is looking at our whole detention plan. We’re making decisions based on if we’re going to move forward at those locations,” he said.

Mr. Lyons said the facilities would be constructed responsibly.

“It’s actually to be retrofitted to become a detention facility, one that we’ll actually be proud of, one that would actually have standards,” he said.

The environmental law in question is the National Environmental Policy Act, which requires a review by the government of the potential environmental impact of significant federal actions. If the agencies find that there might be an adverse impact, they must then do a more rigorous review.

In Maryland, state officials said in court filings that the warehouse project in Williamsport would inevitably lead to adverse environmental consequences. According to court filings, ICE purchased the Williamsport facility for around $100 million, with plans to convert it “into a facility to temporarily house and process” 500 and potentially as many as 1,500 immigrants.

“Converting the Williamsport warehouse into a massive immigration detention facility will have predictable impacts on the environmental, economic, and public health and safety interests of the State of Maryland,” the lawsuit read. “Among other things, these actions are likely to harm the state’s natural resources and environment — including a waterway that is a tributary to the Potomac River and important habitat to state-protected species.”

District Judge Brendan Hurson appeared to agree with that argument, saying the agency had not addressed key requirements of the National Environmental Policy Act.

“Had D.H.S. done so, it likely would have found that the rapid transformation of a cargo-processing facility with four toilets and two water fountains into a temporary residence and workplace for hundreds, if not thousands, would jeopardize the health and safety of the surrounding ecosystem in myriad ways, most notably through the likely overtaxing of the sewer system,” the judge wrote.

Allison McCann and Albert Sun contributed reporting.