Secretary of State Marco Rubio is arguing that the presence of two Hong Kong companies and other Chinese firms violates a treaty Panama has with the U.S.

U.S. Secretary of State Marco Rubio on Sunday warned Panama's President Jose Raul Mulino that Washington will "take measures necessary" if Panama does not immediately take steps to end what President Donald Trump sees as China's influence and control over the Panama Canal.

US Secretary of State Marco Rubio warned Panama to reduce Chinese influence over the Panama Canal, hinting at potential US action. Panama's President José Raúl Mulino acknowledged the concerns but affirmed Panama's control over the canal,