Among the countries for which waivers for certain programs have been submitted are Panama, Costa Rica, the Dominican Republic and its neighbor, Haiti. Although Rubio will not be traveling to Haiti, the State Department has already allowed some $41 million in support of an international peacekeeping force there to go ahead.

Secretary of State Marco Rubio said on Thursday he had "zero doubt" that China has a contingency plan to shut down the Panama Canal in the event of a conflict with the U.S. and that Washington intends to address what it sees as a national security threat.