President Donald Trump on Friday threatened a 100-per-cent tax on imports from any country that imposes a tax on digital services from United States companies.

In a post on social media, Trump took aim at European countries that he said are discussing "imminent" implementation of taxes on American companies.

"Please let this statement serve to represent that any Country that imposes such a Tax will immediately be met with a 100-per-cent TARIFF on any and all Goods sent to the United States of America," Trump wrote.

He added that the new tax would supersede any previously negotiated trade deals. Trump said the penalty would apply to any country that moves forward with such a tax, but he singled out European nations in his post.

Trump has repeatedly pushed against foreign efforts to tax or regulate American tech giants. Last year he threatened new tariffs on any country that moved to do so. A post from last August said that digital taxes and regulation "are all designed to harm, or discriminate against, American Technology".

The threat comes ahead of Trump's July 4 deadline for the European Union and United States to approve a tariff deal that caps tariffs on most EU exports at 15 per cent.

-AP