More than 100 years after the construction of the engineering marvel that linked the Atlantic and Pacific oceans — and 25 years after the canal was returned to Panama by the US — the Panama Canal faces renewed intimidation from US President Donald Trump.

Panama has complained to the United Nations over US President Donald Trump's "worrying" threat to seize the Panama Canal, even as it launched an audit of the Hong Kong-linked operator of two ports on the interoceanic waterway.

The canal, which was once owned by the United States but was handed over to Panama decades ago, gives vessels a much shorter route between the Caribbean Sea and Pacific Ocean. While the two countries could end up resolving the issue,