Potential plans range from partnering more closely with Panamanian security forces to a less likely option of U.S. troops' seizing the canal by force, U.S. officials told NBC News.

American access to the Panama Canal, one of several new directives outlined in what amounts to a major overhaul of US strategic priorities, according to a new memo that was sent to senior leaders and reviewed by CNN.

US Southern Command has been given proposals that include collaborating with the Panamanian military - and potentially seizing the canal by force if they don't co-operate