In 2006 the U.S. Department of Homeland Security and the Department of Energy announced the first phase of the Secure Freight Initiative (SFI), which built upon existing port security measures. SFI gave the U.S. government enhanced authority, allowing it to scan containers from overseas for nuclear and radiological materials in order to improve the risk assessment of individual US-bound containers. The initial phase of Secure Freight involved deploying of nuclear detection and other devices to six foreign ports: