The US Trade Representative's office confirmed that the new duties entered into force at 12.01 a.m., reports Efe news.
The tariffs were imposed in response to a ruling on october 2 by the World Trade Organization (WTO) that backed the US in a long-standing dispute over subsidies to European aerospace company Airbus, which Washington claimed were illegal.
In its ruling, which dealt a crushing blow to already-fragile US-EU trade relations, the WTO said that Washington could impose trade sanctions worth $7.5 billion annually on the bloc.
The EU, which is waiting for the WTO to rule on a similar case on US subsidies to American aerospace company Boeing, has warned that it could slap similar tariffs.
The four most affected countries - as a bulk of the tariffs will be applied to their goods - are France, Germany, Spain and the UK as, according to the WTO ruling, they offered loans to Airbus at a lower interest rate than the market, which allowed the company to develop some of its most recent and advanced models.
Among the EU products subjected to an additional 25 per cent ad valorem tariff are fresh cheese, olives and olive oil from Spain; wine and cheese from France; coffee, cookies and waffles from Germany; whiskey and sweets from the UK; and also Italian cheese.
US President Donald Trump boasted on Wednesday that Washington could not lose a tariff war, as had been supposedly proven in the ongoing trade dispute with China, despite no evidence to that claim.
"We're winning; in the case of the EU, $7.5 billion. And Italy has a percentage of that to pay," Trump said during a joint press conference with his Italian counterpart, Sergio Mattarella, at the White House.
( With inputs from IANS )