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.

The U.S. acquired the rights to build and operate the canal in the early 20th century. In a treaty signed in 1979, during the administration of Democratic President Jimmy Carter, the U.S. agreed to turn over control of the canal to Panama at the close of 1999.