The European Union will react "firmly and swiftly" to protect its interests if Washington imposes tariffs on the bloc's goods, said its trade chief Wednesday, rejecting President Donald Trump's claim that US-EU trade ties are unfair.

"It is the very definition of a win-win partnership, and there is nothing unfair," Maros Sefcovic added, as Europe girds for heightened tariff tensions with the United States.

Speaking at the American Enterprise Institute, Sefcovic said the EU sees "no justification for sudden, unilateral tariff increases" by the United States, adding that businesses rely on economic stability and predictability on both sides.

If the United States imposed tariffs on EU products, this would create "unnecessary barriers" to exports, farming businesses and workers on both sides of the Atlantic, said Sefcovic, who is European Commissioner for Trade and Economic Security.

"To protect European interests, we will have no choice but to respond firmly and swiftly," he said, ahead of talks with his US counterparts.

But he stressed that the bloc will do its best to avoid such an outcome.

Sefcovic's trip comes after Trump has threatened sweeping "reciprocal tariffs" on allies and adversaries, taking aim at the EU for being "absolutely brutal" in trade ties with the United States.