http://news.bbc.co.uk/2/hi/business/3059699.stm
The stage is set for a transatlantic trade war after the World Trade Organisation (WTO) found emergency United States steel tariffs were against its rules.
The US has said it will appeal against the decision.
The EU has already drawn up a list of US products - including running shoes, textiles and food - totalling $2.6bn on which it wants to impose sanctions in retaliation.
But analysts say it will make a final attempt to hammer out a solution with US authorities before unleashing a full scale trade war.
'Without justification'
President George W Bush introduced the controversial trade barriers last March, under pressure from steel manufacturers and workers.
The tariffs - of up to 30% on top of normal duties - were designed to protect America's ailing steel industry from a flood of imports.
But they provoked fury in the European Union, Japan and other steel exporting economies, which have rationalised their steel industries to compete in the world market - often at a painful cost in jobs.
On Friday, a three-man WTO panel ruled the tariffs had been introduced without proper justification.
The decision has been expected since March, when details of an interim ruling were leaked.
The EU had earlier warned the US it could face sanctions on its exports if it did not drop the tariffs or lodge an appeal against the WTO ruling within five days.
The case was brought to the WTO by the EU, Japan, South Korea, China, Switzerland, Norway, New Zealand and Brazil.
'Serious injury'
The US argues its tariffs are in line with the WTO's Safeguard Agreement, which allows countries to restrict imports temporarily if they threaten "serious injury" to a specific industry.
But Friday's WTO report said Washington had failed to provide a "reasoned and adequate explanation" of a link between increased imports and "serious injury" caused to US producers.
US Trade Representative spokesman Richard Mills said: "The steel safeguard measures will remain in place" while the ruling is being appealed.
"Safeguard measures are allowed under WTO rules. Many countries have used them. We believe the steel safeguard measures comply with our international obligations.
"In accordance with US law and WTO rules, the safeguard is a temporary measure, designed to help domestic producers adjust to import competition."
But US importers and manufacturers of consumer goods using steel products welcomed the WTO's earlier interim finding.
They said the tariffs had pushed up their costs and were driving thousands out of work to help inefficient steelmakers.