Panama offers cooperation
Mulino painted a rosier portrait of his meeting with Rubio, whom he welcomed at his official residence in the tropical capital's old quarter.
He also announced that Panama would not be renewing an agreement to participate in China's Belt and Road project -- a massive infrastructure initiative spearheaded by Beijing -- which the country had signed onto under a previous administration.
"I don't feel that there is any real threat at this time against the treaty, its validity, or much less of the use of military force to seize the canal," Mulino told reporters.
"Sovereignty over the canal is not in question," he said, proposing technical-level talks with Washington to clear up concerns.
Mulino previously ordered an audit of a Hong Kong-based company that controls ports on both sides of the canal but Trump said the step was not enough.
Mulino, who until Trump's criticism was widely regarded as a staunch US ally, also promised to step up cooperation on the new administration's top priority -- repatriating undocumented migrants.
Mulino offered Rubio the use of an airstrip in the town of Meteti in Darien, the dense, prohibitive jungle that has nonetheless become a major crossing point for migrants seeking to exit South America en route to the United States.
The deportation plan "suits us very well, to be honest," Mulino said.
Former president Joe Biden already sealed a deal after Mulino's election last year to provide $6 million to assist in expelling migrants.
They include Venezuelans and Ecuadorans but also Haitians desperate even for a roundabout way out of their violence-ravaged country. Few are from Panama, one of Latin America's wealthiest countries.
Rubio is expected to focus on migration on the four other stops of his trip -- El Salvador, Costa Rica, Guatemala and the Dominican Republic.
Protests against Rubio
Small but intense protests broke out in Panama ahead of Rubio's visit, with protesters burning him in effigy and police firing tear gas.
The Panama Canal -- which Trump has dubbed a modern "wonder of the world" -- was built by the United States and opened in 1914 at the cost of thousands of lives of laborers, mostly people of African descent from Barbados, Jamaica and elsewhere in the Caribbean.
Jimmy Carter negotiated the agreement that gave the canal to Panama, with the late president seeing a moral imperative for a superpower to respect a smaller country.
Trump takes a vastly different view and has returned to the "big stick" approach of the early 20th century, in which the United States threatened force to have its way.