"There is no decision yet on either of those two options," an EU diplomat said after political directors from the 27-nation bloc met in Stockholm on Thursday.
The diplomat said Swedish Foreign Minister Carl Bildt, whose country holds the rotating presidency of the EU, had called his Iranian counterpart Manouchehr Mottaki earlier this week.
"We are taking things step by step. We are waiting for an Iranian response," the diplomat said. Further meetings of EU officials were scheduled in Stockholm and Brussels on Friday.
The diplomat did not mention a separate proposal that EU nations withdraw their ambassadors from Iran and a second EU diplomat said he did not expect agreement on that on Friday.
Action by Iranian security forces against demonstrators who charged the election had been rigged in favour of incumbent President Mahmoud Ahmadinejad has drawn Western condemnation.
Iranian authorities say the vote was fair.
EU foreign ministers last week urged Iran to swiftly release several Iranian employees of Britain's Tehran embassy and a Greek journalist detained as alleged instigators of the street unrest. They also warned of a "strong and collective response" against intimidation of diplomatic staff. (Reporting by David Brunnstrom and Mark John; Editing by Sophie Hares)
