President Donald Trump has called for the US to retake control of the Panama Canal unless the cost of passage for naval and merchant ships is slashed. Trump’s refusal to rule out the use of force is a throwback to the 19th century era of gunboat diplomacy.

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.

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.

President Trump’s threat to retake the canal came out of the blue, inflaming Panamanians. But Trump’s view is nothing new.

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.