PANAMA CITY— U.S. Secretary of State Marco Rubio told Panamanian President José Raúl Mulino on Sunday that the Central American ally must immediately reduce Chinese influence over the Panama Canal area or face potential retaliation from the Trump administration. Mulino said later that “there is no real threat of retaking the canal or the use of force.”

Rubio, on his first foreign trip as the top U.S. diplomat, held talks with Mulino, who has resisted pressure from the new U.S. government over Panama’s management of the waterway that is vital to global trade.

Speaking on behalf of President Donald Trump, who has demanded that the canal be returned to U.S. control, Rubio told Mulino that Trump had made a preliminary determination that China’s presence in the canal area violates a treaty that led to the United States turning the waterway over to Panama in 1999. That treaty calls for the permanent neutrality of the American-built canal.

“Absent immediate changes, it would require the United States to take measures necessary to protect its rights under the treaty,” the State Department said in a summary of the meeting.

Mulino said there’s no “real threat against the treaty and its validity.”

The warning from Rubio comes as Trump has increased pressure on Washington’s neighbors and allies, including the canal demand. On Saturday, Trump announced he was imposing major tariffs on Canada and Mexico, prompting retaliation from those countries. China also faces Trump tariffs.

Mulino called it a “good-faith meeting” that was “respectful” and “positive” and held “to clear up doubts.” He acknowledged that China’s role in the ports at either end of the canal has raised concerns with Washington. But the president said the consortium controlling them was being audited and that the canal authority would give Rubio a more detailed explanation. Mulino did say Panama would not be renewing its agreement with China’s Belt and Road Initiative when it expires.

Hong Kong-based Hutchison Ports company was given a 25-year no-bid extension to run both ends of the canal. Some think the audit could lead to a rebidding process. Rubio later planned to tour the canal.

About 200 people protested in Panama City, shouting “Marco Rubio out of Panama.”

Mulino said he hoped Rubio’s visit would focus on shared interests such as migration and combating drug trafficking. Rubio’s trip, however, comes as a U.S. foreign aid funding freeze and stop-work orders have halted U.S.-funded programs targeting illegal migration and crime in Central America.

Rubio also pressed Trump’s top focus, curbing illegal immigration, telling Panama’s president that it was important to collaborate and thanked him for taking back migrants.

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 available.