U.S. President Donald Trump’s insistence that he wants to have the Panama Canal back under U.S. control is feeding nationalist sentiment and worry in Panama, home to the critical trade route and a country familiar with U.

In recent weeks, when he was President-elect Donald Trump publicly said that Panama should return the Panama Canal to the United States, and he would not rule out using military force to reclaim it. At his presidential Inauguration on Monday Trump doubled down on saying that his new administration was going to take back the canal.

Trump has suggested using military force to retake the Panama Canal, but such an action would involve complications.

Panamanian President José Raúl Mulino says his nation intends to maintain control of the Panama Canal, after President Trump re-upped his intent to take control of the strategic waterway in his inaugural address.