The decision is expected to provoke retaliation from Washington, which is expected to announce a figure for trade sanctions against Europe possibly running to hundreds of millions of dollars. That move is the first step towards new tariffs against a range of European products, from jam to mopeds, which could begin in July.
The dispute has provoked new transatlantic political strains just as efforts were under way to reach a negotiated settlement in the damaging bust-up over European Union banana imports. The EU argues that the hormone- treated meat endangers children's health and poses a wider cancer risk. a view rejected by America.
A preliminary study released by the EU earlier this month argued that six hormones used to stimulate growth in cattle pose threats of differing severity and adds that children may be specially at risk.
The results of the EU studies will not be available until the end of the year. Brussels has offered to negotiate over compensation through other trade concessions.
A spokesman for the European Commission said yesterday: "The latest scientific evidence means that we cannot lift the beef ban but we want to comply with our WTO obligations, we want to talk to the Americans about compensation and we want open, transparent dialogue with them on the science."