In a report Thursday, the Government Accountability Office said the Trump administration squandered millions of dollars to expand immigration detention. U.S. forces erected a tent city at Guantánamo Bay, Cuba, to house migrants. The camp in Cuba, planned near the prison that held suspected terrorists in the wake of the 9/11 attacks, was built to hold 5,000 detainees. As of June, the average daily population of detainees there was 16, G.

A. O. said. The administration also spent $20.5 million on administrative costs and utilities on the seven warehouses the government purchased in haste and later decided to sell.

And it squandered $7.1 million for food it did not need at one of its new detention camps in Texas, the review found. Neither ICE nor the Homeland Security Department responded to a request for comment. The report is the latest indictment of the spending spree by federal officials to follow through on President Trump’s pledge to detain and deport record numbers of immigrants.

Officials have poured billions of dollars into hiring immigration enforcement officers, purchasing unused warehouses to convert into detention centers and expanding other enforcement operations. As a result, immigrant arrests have reached record levels and illegal border crossings have come to a halt. The spending blitz has also drawn scrutiny from critics and watchdogs.

Immigration and Customs Enforcement launched six major expansion efforts without a strategic plan in place and has since scaled back four of them, the G. A. O. said.

As of July of this year, ICE spent more than $2.5 billion on warehouses and other facilities to house detainees but did not assess the long term costs, the congressional watchdog said. In its report, the G. A.

O. recommended that ICE develop a broad strategic plan to advise its detention expansion efforts with stated goals and budgets. ICE concurred. The report included several costly, high-profile efforts by the Trump administration to expand detention that were ultimately scrapped that G.

A. O. considered wasteful. In one of its earliest efforts, the Trump administration planned to house 30,000 immigration detainees on the Guantanamo Bay Naval Base.

The Defense Department spent $2.85 million to build tents to house 5,000 migrants, but the shelters did not meet federal detention standards and as a result were never used. Ultimately, the plan was scrapped. As of June, the average daily population of detainees there was 16.

ICE also partnered with the Defense Department to use military camps to house detainees, including one on an Army base in El Paso, Texas, called Camp East Montana. The government wasted $11.5 million on detainee services over a two-week period when the facility was empty. The camp was built to hold 5,000 detainees, but had about 1,600 as of February of this year.

Between October and March, ICE spent $7.1 million on meals it did not need. After purchasing 11 warehouses for $1 billion to hold detainees, ICE decided to sell seven of them. To break even, the government must sell the seven warehouses for exactly what it paid for them: $707 million.

And in the process of purchasing the seven warehouses it no longer wants, ICE spent $7.7 million in sunk costs for zoning assessments and title insurance as well as $12.8 million on utilities and security for the buildings even though they are not in use.