The UK Government has not asked for a specific legal opinion from the European Commission on Scotland's place in the EU in the event of independence.
A "concrete scenario" for potential independence would be needed before details can be given, an EC spokesman said.
"We have not defined the content or timing of a 'concrete scenario' but one clarification that is important is that it would need to come from a member state, in this case the UK Government," the spokesman said.
No such formal approach has been made, he said.
The comment follows a week of pressure on First Minister Alex Salmond over his position on whether Scotland would enjoy a smooth transition as a new member state or be forced to join the queue with other aspiring EU members.
The Scottish Government admitted last week that it did not seek specific advice on a future place in the EU, despite initially going to court to keep that information from the public.