A new report released on Monday found that the U.S. government spent nearly 18 billion dollars on federal immigration enforcement in last fiscal year, more than on all other principal federal criminal law enforcement agencies combined.

According to the report from the nonpartisan Migration Policy Institute, the Obama administration spent 17.9 billion dollars on immigration enforcement programs by Customs and Border Protection, Immigration and Customs Enforcement, Department of Homeland Security and the US Visitor and Immigrant Status Indicator Technology program in fiscal year of 2012 ending in last September.

The total spending was about 24 percent higher than the collective spending for all other federal criminal law enforcement agencies, including the FBI, Drug Enforcement Administration, Secret Service, U.S. Marshals Service and Bureau of Alcohol, Tobacco, Firearms and Explosives.

The report said U.S. federal government's immigration enforcement spending has totaled nearly 187 billion in the 26 years since the passage of the Immigration Reform and Control Act.

"Today, immigration enforcement can be seen as the federal government's highest criminal law enforcement priority, judged on the basis of budget allocations, enforcement actions and case volumes," said MPI Senior Fellow Doris Meissner, who co-authored the report.

The report, entitled Immigration Enforcement in the United States: The Rise of a Formidable Machinery, said deportations have reached record highs, apprehensions at the U.S.-Mexico border fell to 40-year lows in 2011, more non-citizens than ever before are in immigration detention, and immigration enforcement has been granted new standing as a key tool in the country's counterterrorism strategies.

More than 4 million non-citizens, primarily unauthorized immigrants, have been deported from the United States since 1990, said the report. Removals surged from 30,039 in the fiscal year of 1990 to 391,953 in the fiscal year of 2011.

"Changes to the immigration system over recent decades have focused almost entirely on building enforcement programs and improving their performance. Yet even with record-setting expenditures and the full use of statutory and administrative tools, enforcement alone, no matter how well administered, is insufficient to answer the broad challenges that immigration poses for America's future," said Meissner.