US president Donald Trump has said America will begin “cutting off, or substantially reducing” aid to three Central American nations over a migrant caravan heading to the US southern border.

Mr Trump tweeted: “Guatemala, Honduras and El Salvador were not able to do the job of stopping people from leaving their country and coming illegally to the U.S.”

The three countries combined received more than 500 million dollars (£382 million) in funding from the US in the last financial year.

Mr Trump has raised alarm over a group of thousands of migrants travelling through Mexico to the US, saying: “Sadly, it looks like Mexico’s Police and Military are unable to stop the Caravan.”

The tweets marked the latest escalation by the US president, who is seeking to re-inject immigration politics into the national conversation in the closing weeks of the American mid-term elections.

On a three-day campaign visit to western states last week, Mr Trump raised alarm over thousands of migrants travelling through Mexico to the US and threatened to seal off the Mexican border if they are not stopped.

A Pentagon spokesman, Army Lt Col Jamie Davis, said the Pentagon has received no new orders to provide troops for border security.