LONDON (Reuters) -Premiums for consumers buying aluminium on the physical market in the United States hit a record 60 cents a lb or $1,323 a metric ton on Thursday after U.S. President Donald Trump imposed higher tariffs on U.

Donald Trump's increased tariffs on steel and aluminium products imported into the United States are now in effect, meaning foreign importers face 50 per cent levies on top of their current costs.

The treasurer has described the US tariffs as harmful for the global economy, warning Australia will not be immune from the flow-on impacts.