Some U.S. lawmakers and officials are touting a nearly half-century-old treaty between the United States and Panama to justify the Trump administration's threat to reclaim the Panama Canal - provided it can show the strategic waterway's operation is under threat.

Jose Raul Mulino said he won't discuss control of the canal during the secretary of state's visit. Rubio, in contrast, said "we're going to address that topic."

Experts dispute President Donald Trump’s claims that the Panama Canal is controlled by China and overcharging U.S. ships.