The US Immigration and Customs Enforcement service, also called ICE, has recently become the investigative department that is by far the largest such unit and is a component of the Department of Homeland Security, or the DHS. One of the main responsibilities of ICE is to find the vulnerable areas of the US borders, eliminate the problems and make the borders as secure as possible.

US Immigration and Customs Enforcement is also responsible for much of the security associated with the US borders in aspects of economics, transportation issues and the overall security of the infrastructure.

The US Immigration and Customs Enforcement agency is also responsible for enforcing approximately 400 federal statues inside of the US borders. As well, it has agent attaches who are posted at all of the primary United States embassies overseas.

Because of this and the US immigration policies, ICE and the special agents of the agency, are considered to be empowered with the broadest investigative authority that exists within the US federal government.

The mission statement of ICE is to protect the United States of America and to uphold the public safety by identifying and targeting the money, people and/or materials that are used in support of both terrorist and criminal activity within the US. The ICE agency motto is, "Integrity, Courage and Excellence."

The US Immigration and Customs Enforcement agency is under the direction of an Assistant Secretary. This position is by appointment and considered a sub-cabinet level.

The ICE Assistant Secretary is appointed by the President of the United States and then must be confirmed by a vote of the US Senate. Therefore, he or she reports to and is under the direction of the Secretary of Homeland Security.

ICE was formed under the provisions of the Homeland Security Act of 2002 which was passed after the tragic events of September 11, 2001. When the Department of Homeland Security, or DHS, was formed in accordance with the Homeland Security Act, all of the functions and authority of several different revenue and border enforcement agencies were brought together and rebuilt as the US Immigration and Customs Enforcement agency.

As a result of this restructuring, ICE is the investigative arm of the DHS. It is the largest in manpower and resources and it is also the second largest contingent of support and contribution to the efforts of the Unites States' Joint Terrorism Task Force, second only to the contributions of the FBI.

Because of the way the various agencies were restructured under the new DHS, the newly formed ICE is now made up of intelligence resources from the US Customs Service, combined with the law enforcement functions of the Immigration and naturalization Service and the US Federal Protective Service. As a result, ICE is now responsible for protecting all federal government buildings within the borders of the United States.

Since the US Immigration and Customs Enforcement department has been given such a huge law enforcement responsibility and with such board authority that it has, the hiring process for new agents is competitive and rigorous, and the standards are very high.