Secretary of State Marco Rubio sent a warning about the Panama Canal, saying the current status of the trade route is “unacceptable.”

According to a summary of Rubio’s meeting with Panamanian president José Raúl Mulino released by the State Department, Rubio said there would have to be “immediate changes” to how the U.S. operates with the canal.

“Secretary Rubio informed President Mulino and Minister Martínez-Acha today in Panama City to address critical regional and global challenges,” the summary said.

The State Department said Rubio and President Trump have determined that the threat posed by the Chinese Communist Party over the canal’s operations are in violation of the Treaty Concerning the Permanent Neutrality and Operation of the Panama Canal.

“Secretary Rubio made clear that this status quo is unacceptable and that absent immediate changes, it would require the United States to take measures necessary to protect its rights under the Treaty,” the release said.

Rubio thanked Mulino, praising his regional leadership in support of Venezuela democracy efforts and said it was a “productive conversation.”

Just days ago, Mulino said it would be “impossible” to negotiate about returning the canal to U.S. control.

Mulino spoke to reporters and said he hoped to talk to U.S. officials about immigration, security and the continued international fight against drug trafficking. It was unclear if he was able to discuss the issues with Rubio.

President Trump has continued his calls for retaking the Panama Canal, one of his priority issues in his first days in office. He criticized the Carter administration for selling the U.S.-built canal to Panama.  He also was upset about high transit prices and the Chinese influence over the area.