Turkey has described an EU declaration criticising Ankara's refusal to recognise Cyprus as unjust, one-sided and politically motivated.
Turkey keeps 40,000 troops in northern Cyprus
The bitter words from foreign ministry spokesman Namik Tan come less than two weeks before Turkey and the EU are due to begin talks on Turkish membership.
The EU declaration said that Turkey would have to recognise Cyprus before it could join the EU.
The talks, supposed to begin on 3 October, are likely to last 10 years.
"We regret the publication of this counter-declaration. It has a style which does not accord well with the traditional spirit of co-operation that has existed between Turkey and the EU over a period of more than 40 years," Mr Tan said.
He also called on the EU to keep promises to lift the economic blockade against northern Cyprus and to provide financial aid to the region.
EU DECLARATION KEY POINTS
Member states "regret" Turkey's July declaration refusing to recognise Cyprus
Member states expect full implementation of the customs union and removal of "restrictions on means of transport"
Failure to implement the customs union in full will "affect overall progress in the negotiations"
Recognition of all member states is "a necessary component of the accession process"
The declaration ignored the "rights and expectations of the Turkish Cypriot people" Mr Tan said, describing this as a "serious injustice".
Turkish officials say the EU's efforts to end the isolation of the Turkish Cypriots have been blocked by Cyprus, a member of the EU since May 2004.
The EU declaration came in response to an earlier declaration by Turkey in July, saying that its extension of a customs union with the EU to all new member states did not imply recognition of Cyprus.
Since then, Turkey has continued to block Cypriot ships and aircraft from its ports and airports.
Wednesday's declaration says the EU expects full implementation of the customs union and removal of "restrictions on means of transport".
It also says the EU will "evaluate full implementation" of the customs union in 2006.
Mr Tan said this was a "new element" in what he described as a "one-sided and politically motivated" text that could weaken the UN peace process for the divided island.
The process came to a halt last year after Turkish Cypriots voted in favour of a peace plan drawn up by UN Secretary-Genral Kofi Annan, and Greek Cypriots voted against.
Turkish newspapers on Thursday reflected a mood of frustration with the EU.
"The growing mood is such in Turkey that if the government were to announce that it will suspend relations with the EU, the support it would get from the public would soar," foreign affairs commentator Semih Idiz wrote in the English-language Turkish Daily News.
He added that Turks felt that Greek Cypriots were being "rewarded" for rejecting the UN peace plan, and were beginning to think "enough is enough".
Another commentator, Asli Aydintasbas, speculated that even if membership talks begin as planned on 3 October, they could easily break up shortly afterwards.
Before the talks can begin, EU member states have to agree a negotiating framework which divides the entry talks with Turkey into 35 policy areas.
A spokesman for the EU's UK presidency said on Wednesday that only one country, Austria, still had objections to the proposed framework, and that he was confident the problem could be resolved in time.
Austria has long argued that the framework should mention the possibility that Turkey will ultimately be offered a "privileged partnership" rather than full membership.