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.

As he took office Monday, President Trump repeated his goal of taking back the Panama Canal. China is “operating the Panama Canal,” Trump said, and accused the canal authority of overcharging the U.S.

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.