Secretary of State Marco Rubio embarks soon on his inaugural trip as the United States’ top diplomat. His first stop, Panama could prove to be the most contentious on the itinerary.

Panamanian President Jose Raul Mulino on Thursday ruled out discussing control over the Panama Canal in a meeting with U.S. Secretary of State Marco Rubio, who is set to visit the Central American country in his first official trip abroad this weekend.

Secretary of State Marco Rubio declared Thursday that President Trump’s interest in taking control of Greenland and the Panama Canal “is not a joke” and vital to US national security interests. “This is not a joke,