PANAMA CITY (AP) — Panama President José Raúl Mulino said Thursday there will be no negotiation with the United States over ownership of the Panama Canal, and he hopes U.S. Secretary of State Marco Rubio’s upcoming visit will allow them to focus on shared interests including migration and combating drug trafficking.

Being the destination for the first overseas visit by the top U.S. diplomat would have been big for Panama in any case, but Rubio comes as the emissary of U.S. President Donald Trump, who has repeatedly suggested the U.S. retake the Panama Canal.

On the day of his inauguration, Trump claimed that U.S. ships were being “severely overcharged and not treated fairly in any way, shape or form,” noting that "above all, China is operating the Panama Canal.” He had previously said the U.S. could demand the canal be returned.

Mulino tried to downplay the tension at his weekly press conference Thursday. He spoke of wanting to clarify confusion about China’s role in the canal — a Hong Kong consortium manages ports at both ends, but Panama controls the canal – and blamed a predecessor for establishing diplomatic relations with China.

“It’s impossible, I can’t negotiate,” Mulino said when asked about returning the canal to U.S. control. “That is done. The canal belongs to Panama.”

The United States built the canal in the early 1900s as it looked for ways to facilitate the transit of commercial and military vessels between its coasts. Washington relinquished control of the waterway to Panama on Dec. 31, 1999, under a treaty signed in 1977 by President Jimmy Carter.

“The only thing that I want is to clear all the garbage from the path, clean the table and be able to speak with the United States and very frankly” about issues including immigration, security and the fight against drug trafficking, Mulino said.

Rubio is scheduled to meet with Mulino Sunday and visit the canal.