The European Union's trade chief said the 27-member bloc is committed to securing a trade deal with the US based on "respect" not "threats".
It comes after US President Donald Trump threatened to slap a 50% tariff on all goods sent to the US from the EU.
"The EU's fully engaged, committed to securing a deal that works for both," EU Trade Commissioner Maros Sefcovic said after a call with US Trade Representative Jamieson Greer and Commerce Secretary Howard Lutnick.
"EU-US trade is unmatched & must be guided by mutual respect, not threats. We stand ready to defend our interests."
Earlier on Friday, Trump expressed impatience with the pace of ongoing EU-US trade negotiations, saying his plan to raise tariffs on 1 June was set.
Writing on social media, Trump said: "Our discussions with [the EU] are going nowhere," adding that there would be no tariffs for products built or manufactured in the US.
"I'm not looking for a deal – we've set the deal," he told reporters later, before immediately adding that a big investment in the US by a European company might make him open to a delay.
The EU is one of the Washington's largest trading partners, sending more than $600bn (€528bn; £443bn) in goods last year and buying $370bn worth, US government figures show.
