The EU and Japan held crunch talks with their US counterparts in Brussels on Saturday hoping to get "clarity" on President Donald Trump's controversial new steel and aluminium tariffs.
Trump's announcement of duties of 25 percent on imported steel and 10 percent on aluminium has stung the European Union and triggered warnings of an all-out international trade war.
Brussels has prepared a list of US products to hit with countermeasures if its exports are affected by the tariffs, but says it hopes to join Canada and Mexico in being exempted. Japan has decried the "grave impact" the Trump measures could have on the world economy.
The EU's top trade official Cecilia Malmstroem and Japanese Economy Minister Hiroshige Seko began preliminary talks in Brussels ahead of the sitdown with US Trade Representative Robert Lighthizer.
The talks, initially set to address China's over-supply of steel, have long been in the diary but after Trump's dramatic announcement they are now a de facto crisis meeting.
"Dialogue is always the prime option of the European Union," Malmstroem told reporters on Friday, saying Brussels was "counting on being excluded" from the new duties.
She predicted a "long day" of talks on Saturday, while European Commission Vice President Jyrki Katainen sought to play down expectations, saying it was "a meeting, not THE meeting".
Katainen said Brussels wanted "clarity" on how the tariffs will be implemented and was ready to enforce retaliatory measures to protect European interests if needed.
"We are prepared and will be prepared if need be to use rebalancing measures," Katainen said.
Along with a huge range of steel products, the EU's hit list of flagship American products lined up for counter measures includes peanut butter, bourbon whiskey and denim jeans.
Germany -- singled out for particular criticism by Trump -- accused Washington of protectionism, calling the tariffs an "affront to close partners".
German Chancellor Angela Merkel urged dialogue and warned that "no one can win in such a race to the bottom".
French President Emmanuel Macron on Friday warned his US counterpart Trump against forging ahead with the planned tariffs, saying they risked provoking a mutually destructive "trade war".
Trump said the tariffs, which will come into effect after 15 days, will not initially apply to Canada and Mexico. He also added Australia to the list of likely carve-outs.
Complicating matters, Trump indicated on Friday that Australia's carveout was linked to an unspecified "security agreement" outside of trade policy.
This shed some light on the tycoon's specific barbs against Germany -- the biggest economy in the European Union -- that have finger-pointed Berlin for contributing much less than the US towards the funding of NATO.
The EU exports around five billion euros' ($4 billion) worth of steel and a billion euros' worth of aluminium to the US each year, and the European Commission, the bloc's executive arm, estimates Trump's tariffs could cost some 2.8 billion euros.
Brussels is also looking at "safeguard" measures to protect its industry -- restricting the bloc's imports of steel and aluminium to stop foreign supplies flooding the European market, which is allowed under World Trade Organization rules.
The EU and Japan last year formally agreed the broad outlines of a landmark trade deal that was announced as a direct challenge to the protectionism championed by Trump.