Treaties ratified by the Senate in 1978 established permanent neutrality, but some Republicans regret that decision.

Trump named Miami-Dade County Commissioner Kevin Marino Cabrera as his choice for the post after suggesting that the US should take control of the Panama Canal – a proposal he first floated over the weekend while claiming that Panama is “ripping off” American ships that pass through the waterway.

It's unclear how the issue of ownership of the Panama Canal became a talking point for President-elect Donald Trump this week, but the question has a long political history.