The EU's trade chief has said German chancellor Angela Merkel and French president Emmanuel Macron will press US leader Donald Trump this week to exempt the 28-member bloc permanently from US steel and aluminium tariffs.
Trade Commissioner Cecilia Malmstrom said the EU will be ready to hit back with measures of its own as of next month if the punitive tariffs are imposed.
The United States and the EU are holding high-level talks to address the issue but Ms Malmstrom insisted Washington should not count on any concessions from the EU.
She said: "We expect an unconditional and permanent exception."
Mr Macron arrives in Washington on Monday while Mrs Merkel travels on Thursday.
Meanwhile, Ms Malstrom said a sweeping new trade deal with Mexico is a "powerful signal to the rest of the world" - including the Trump administration.
She said the preliminary deal, agreed on Saturday and to be finalised later this year, shows that "with increasing protectionism in certain parts of the world, many of us do believe good trade agreements can be made ... to the benefit of consumers and companies".
The deal comes as Mr Trump's America-first policies have thrown US-Mexico trade into uncertainty and stalled efforts for a US-EU trade deal.
The EU-Mexico deal removes tariffs on cheese, chocolate, pasta and other foods. It updates and expands a two-decade-old agreement to include financial services and online commerce, among other sectors.