"I've asked Secretary of State Marco Rubio to immediately take care of, and memorialize, this situation!" the president wrote.

Trump demands U.S. ships travel free through Panama and Suez canals, citing America's role in building and protecting the world's key shipping routes.

The Panamanian president, Jose Raul Mulino, said that toll fees were regulated by the Panama Canal Authority (ACP), an autonomous governing body that oversees the trade route.