Trump last week carried out a threat he made earlier this year by announcing he would impose $50 billion worth of tariffs on Chinese goods.
The tariffs, which took effect at midnight, further fuelled jitters on world stock markets that were already alarmed by trade tensions between the United States and China.
The European Union retaliated against President Trump's steel and aluminum tariffs Friday with tariffs on about $3.3 billion worth of American goods, including bourbon, orange juice, peanut butter, and motorcycles.
The 28-nation EU was first expected to do so only next month but EU Trade Commissioner Cecilia Malmstrom said they would introduce "rebalancing" tariffs on about 2.8 billion euros' ($3.4 billion) worth of United States products this week.
It had previously registered the move with the World Trade Organization (WTO).
The equivalent value of €6.4 billion in European Union steel and aluminium exports that are now facing United States tariffs.
Trump imposed tariffs of 25 per cent on European Union steel and 10 per cent on aluminum on June 1.
From blue jeans to motorbikes and whiskey, the EU's hit-list of products targeted for tariffs with the USA reads like a long list of emblematic American exports.
Earlier this month, Mexico imposed a series of tariffs on $3 billion worth of USA exports of pork, apples, potatoes, bourbon as well as different types of cheese.
Some of the products chosen are created to target the states of Republicans, who are seeking to retain control of both chambers of the US Congress in November elections.
And he is threatening to impose another national security-based tariff on imports of cars, trucks and auto parts. But if both exports and sales of U.S. companies inside China are measured, the United States has a surplus of US$20 billion with China, according to Deutsche Bank AG.
China is "fully prepared" to respond to any new list of U.S. tariffs, according to a commerce ministry spokesman, who said the nation will use a combination of quantitative and qualitative measures. "The logic of that is what companies throughout the country are feeling".
One thing that may cause Beijing to hold back from a full-scale attack on American companies is concern about the impact it would have on the domestic economy.