The exercise will take place from October 9 to 29 and involve 50 Marines, who will travel to Panama aboard a US transport plane, Panama's ministry for public security said.

Panama does not have its own army. Its security forces are made up of the police, border police and coastguard.

The security ministry said the training aimed to "increase interoperability, improve capabilities, and strengthen regional security in one of the most demanding environments on the planet."

The announcement comes amid fears of a US attack in Venezuela, which lies around 500 nautical miles (around 575 land miles, or 925 kilometers) east of Panama, on the Caribbean coast.

US President Donald Trump has sent eight warships and a nuclear submarine to the southern Caribbean as part of a stated plan to combat drug trafficking, but which appears chiefly aimed at pressuring his arch-foe Venezuelan President Nicolas Maduro.

US forces have destroyed at least three suspected drug boats in the Caribbean in recent weeks, killing 14 people.

Trump has also sent 10 fighter jets to Puerto Rico, a US Caribbean territory north of Venezuela.

The naval build-up is the biggest in the region since the December 1989 invasion of Panama by the United States.

The presence of US troops in the Central American country has been a sensitive issue ever since the intervention to topple Panamanian leader General Manuel Noriega, which caused hundreds of civilian deaths.

The United States withdrew the last of its troops and handed back control of the Panama Canal in 1999.

Since returning to office this year, Trump has sought to reestablish US influence over the vital shipping channel.

In a major concession, Panama in April signed an agreement allowing for US troops to deploy to a string of bases along the canal.

Panama however ruled out allowing a permanent US military presence.