US President Donald Trump threatened new tariffs on products from the European Union in retaliation for the bloc’s US$1 billion (€890 million) fine of Alphabet’s Google.

The president in a social media post on Friday said the US would launch a trade investigation “into the practice of ‘ROBBING’ American Companies and, in turn, the American Taxpayer”.

“The penalties will be entirely reversed and, we anticipate, a substantial TARIFF to be placed on them at the earliest possible moment,” Trump posted.

The president has frequently made tariff threats against the largest US trading partners, and has followed through on some of them while retreating from others.

Trump said his administration would carry out the probe under Section 301 of the Trade Act, his new favoured legal authority to rebuild the tariff wall that was pierced earlier this year by the US Supreme Court

Trump’s threat comes on the heels of his decision to impose duties of at least 10 per cent on products from around 60 trading partners, including the EU, citing the desire to limit goods made with forced labour.