Escalating a trade war with Europe, President Donald Trump said his administration will counter the European Union's new tariffs on the US.

Trump's tariff policies have rattled the stock market and raised fears of an economic slowdown, increased inflation and a global trade war.

European Commission President Ursula von der Leyen said as the United States is “applying tariffs worth 28 billion dollars, we are responding with countermeasures worth 26 billion euros,” or about $28 billion.