US President Donald Trump has threatened to impose tariffs and launch a formal trade investigation on the European Union over its recent antitrust penalty against Google.

In a post on his Truth Social platform, Trump accused Brussels of engaging in 'illegal and highly unethical conduct' and vowed to initiate a 301 Investigation under the 1974 Trade Act.

The move comes amid ongoing tensions between Washington and Brussels, with the EU fining Google 890 million euros for breaching the Digital Markets Act.

The penalties, which target Google's favoring of its own services in search results and restrictions on app developers, have drawn criticism from US officials who warn of risks to transatlantic trade.

Trump's threats reflect his broader strategy to rebuild his tariff wall, following a Supreme Court ruling that invalidated many of his previous levies.The EU has remained firm, insisting it will enforce its digital regulations regardless of US pressure.