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.

Panama’s president reiterated on Sunday that Panama’s sovereignty over the Panama Canal is not up for debate, saying that during talks with US Secretary of State Marco Rubio that he had addressed the United States’ concerns over China’s presence around the vital waterway.

The port of Cristobal in Colon, Panama. The Panama Ports Company, a unit of Hutchison Port Holdings -- part of Hong Kong's CK Hutchison conglomerate -- operates ports at both ends of the waterway: at Balboa on the Pacific and Cristobal on the Atlantic. © Reuters