PANAMA CITY – U.S. Secretary of State Marco Rubio is meeting Panama’s president Sunday on the opening stop of his first foreign trip as America’s top diplomat as President Donald Trump increases the pressure on Washington’s neighbors and allies, including a demand for the Panama Canal to be returned to the United States.

A day after Trump announced he was imposing major tariffs on Canada and Mexico, prompting retaliation from those countries, Rubio was set for perhaps a less confrontational and more diplomatic approach. After talks with President José Raúl Mulino, Rubio planned to tour an energy facility and then the canal, the object of Trump’s intense interest.

Mulino has said there will be no negotiation with the U.S. over ownership of the canal, and some Panamanians have staged protests over Trump’s plans. Mulino said he hoped Rubio’s visit would focus on shared interests such as migration and combating drug trafficking.

Rubio will be pressing Trump’s top focus — curbing illegal immigration — but has also said he will be bringing the message that the U.S. wants to reclaim control over the Panama Canal despite intense resistance from regional leaders to combat China’s growing influence in the hemisphere.

In a Wall Street Journal opinion piece on Friday, Rubio said mass migration, drugs and hostile policies pursued by Cuba, Nicaragua and Venezuela have wreaked havoc, and port facilities at the either end of the canal are run by a China-based company, leaving the waterway vulnerable to pressure from the Beijing government.

“We’re going to address that topic,” Rubio said a day earlier. “The president’s been pretty clear he wants to administer the canal again. Obviously, the Panamanians are not big fans of that idea. That message has been brought very clear.”

The American-built canal was turned over to the Panamanians in 1999 and they object strongly to Trump’s demand to hand it back.

Despite Mulino’s rejection of any negotiation over ownership, some believe Panama may be open to a compromise under which canal operations on both sides are taken away from the Hong Kong-based Hutchison Ports company, which was given a 25-year no-bid extension to run them. An audit into the suitability of that extension is already under way and could lead to a rebidding process.

What is unclear is whether Trump would accept the transfer of the concession to an American or European company as meeting his demands, which appear to cover more than just operations.

Rubio’s trip, which will also take him to El Salvador, Costa Rica, Guatemala and the Dominican Republic, comes amid a freeze in U.S. foreign assistance. The State Department said Sunday that Rubio had approved waivers for certain critical programs in countries he is visiting but details of those were not immediately available.