"It is a political act," French Foreign Minister Jean-Yves Le Drian told reporters after a meeting of EU counterparts in Bucharest. "It is a gesture to protect European companies."

Britain's Jeremy Hunt said the three countries were working closely with Tehran to finalise arrangement to allow for humanitarian, pharmaceutical, agricultural and consumer trade.

"Registration is a big step, but there is still more work to be done," Hunt said.

(Reporting by Alissa de Carbonnel and Robin Emmott)