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.

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.

President Donald Trump has directed the Pentagon to prepare plans for carrying out his threat to "take back" the Panama Canal, including by military force if needed, two U.S. officials familiar with the situation told NBC News Thursday.