Donald Trump has refused to rule out using military force to retake the Panama Canal that was returned by the US to Panama decades ago.

As his inauguration nears, the president-elect has ramped up his threats to take back the critical shipping artery in order to secure the flow of US trade, reduce “exorbitant” shipping fees and counter perceived Chinese influence in the area.

Yet the image in 2018 of a worker chiselling the Trump name off a tower in Panama City may also hold a more personal explanation for renewed interest in the waterway.

Who controls the Panama Canal?

The canal, which was built in Central America by the US more than a century ago, connects the Atlantic and Pacific oceans and is regarded as one of the world’s most important routes for maritime trade.

It allows around 14,000 ships a year to cut out the 7,000 nautical mile trip around Cape Horn in South America.

The US operated the 51-mile waterway through Panama until, in the wake of anti-American riots, Jimmy Carter, then-president, signed a 1977 treaty to relinquish control of the canal by the end of the century.

Panama took full control of the canal in 1999, which it operates through the Panama Canal Authority (PCA).