On 6 August, Resolution 661 placed economic sanctions on Iraq. Resolution 665 followed soon after, which authorized a naval blockade to enforce the sanctions. It said the "use of measures commensurate to the specific circumstances as may be necessary ... to halt all inward and outward maritime shipping in order to inspect and verify their cargoes and destinations and to ensure strict implementation of resolution 661." On 12 August, the naval blockade of Iraq begins. On 16 August, Secretary Dick Cheney orders U.S. naval ships to stop all cargo and tankers leaving and entering Iraq and Kuwait.