The US has decided to challenge the EU's de facto moratorium on genetically modified foods in the WTO, senior administration sources said.
"We've been pushed against a wall here," a senior administration official told AFX News, a subsidiary of AFP, on condition of anonymity, adding that a case is expected to be filed by "mid-June" at the latest.
"Sooner is probably more likely," the official said. Officials are still debating the timing of filing the legal papers. At issue is whether to file the case before or after the upcoming Group of Eight summit in Evian, France.
US President George W. Bush is set to travel to the southern French coast early next month for the annual gathering of the heads of state of Britain, Canada, France, Germany, Italy, Japan, Russia and the US.
Richard Mills, spokesman for US Trade Representative Robert Zoellick, whose office would lodge the complaint, declined to comment on the decision to go ahead with the case, saying "the EU's moratorium is illegal under WTO rules and needs to be lifted."
A group of EU countries including France has placed a moratorium on approving GMO imports, effectively halting the trade.
The US contends that the ban, applied since 1999, harms its exports of maize, cotton and soya.
Washington has considered filing a case against the EU for several months, but delayed because of the war with Iraq, officials have said.
In January, Zoellick stunned reporters when he announced that he "personally" held "the view that we now need to bring a case" in the WTO even though there was not an official government consensus on the matter.
Zoellick at that time was careful to note that a cabinet-level meeting hosted by the National Security Council still needed to take place before a decision could be made.
A formal meeting including the heads of the Agriculture, Commerce and State Departments is no longer necessary, an official said.
"There's been inter-agency consultation at that level but without a meeting," the official said, "the consensus is there."
Senate Finance Committee Chairman Charles Grassley, who has been a vocal proponent for filing a case, separately summoned a group of senior administration officials to his Capitol Hill office this week to press for filing a case.
EU Trade Commissioner Pascal Lamy has said in recent months that if the United States did file a case, the EU would win.
"We would win a case like this," Lamy told reporters in Washington after meetings with US lawmakers and administration officials, including Zoellick.
And EU officials have suggested that there would be a consumer backlash against American goods resulting in boycotts of American food products.