The move came after Japan halted imports yesterday of some types of wheat from the US following the discovery of an experimental strain that was tested by Monsanto but was never approved.
"The Commission is following carefully the presence of this non-authorised GM wheat in Oregon in order to ensure that European consumers are protected from any unauthorised GM presence and make sure that the EU zero tolerance for such GM events is implemented," EU's consumer protection office said.
Shipments that test positive should not be sold, but current information from the US Food and Drug Administration indicated the wheat posed no threat to human health, it said.
The European Union imports more than 1 million metric tons (1.1 million tons) of US wheat each year. Eighty per cent of that was soft white wheat, the majority of which is exported to Spain, officials said.
European consumers have generally objected more strongly to genetically modified foodstuffs than Americans.
