The Prime Minister, Mr Mesut Yilmaz, said yesterday Turkey would withdraw its application to join the European Union if the group did not include it in a list of candidates for membership.
"Prime Minister Yilmaz announced that Turkey would withdraw its full membership bid by June if the EU does not change its position," he said during a fuel stop in Brussels en route to an official US visit.
Mr Yilmaz said an EU summit including Turkey must be held by June to avoid the withdrawal of Ankara's application, first put forward in 1963.
He promised to freeze relations with the EU on Sunday after an emergency cabinet meeting to discuss the group's decision to exclude Turkey from its formal list of 11 future members.
Mr Yilmaz was particularly incensed by a series of conditions, from human rights reforms to improved relations with rival Greece, attached to the invitation to the EU enlargement conference.
The European Union tried yesterday to reassure Turkey it has a place in Europe, but remained unrepentant over conditions set by EU leaders for full membership negotiations.
"We did not want to say no to Turkey," the Luxembourg Prime Minister, Mr Jean-Claude Juncker, told the European Parliament, reporting on the Luxembourg summit which decided to leave Turkey off the invitation list for formal EU membership talks.
"We consider that Turkey is a great European nation and the place of Turkey is within the European family. But I would like our Turkish friends to understand, we are not a club of Christians, but a club with certain rules."