European Union countries have failed to agree on whether to start entry talks with Croatia, which has not yet handed over a top war crimes suspect.
Gen Ante Gotovina is accused of war crimes against ethnic Serbs
The EU had urged Croatia to detain and hand over Gen Ante Gotovina to the international war crimes tribunal.
A group led by the UK and Germany insists Zagreb must co-operate with the tribunal before talks can start.
EU diplomats will meet again next week to discuss the issue but correspondents say a postponement seems certain.
The BBC's Chris Morris says most member states at the ambassadorial meeting in Brussels agreed that Croatia was not doing enough to co-operate with the war crimes tribunal in The Hague.
A group of central European countries led by Austria argued that talks with Croatia should start regardless.
Our correspondent says EU foreign ministers are expected to agree next week on the mandate for negotiating with Croatia, but it will not be adopted until the Croats do more to find the fugitive Gen Gotovina.
He is accused of ordering the killing of more than 100 ethnic Serbs and expelling 150,000 more during an offensive in 1995 to recapture Croatian lands seized by Serb forces.
If we send the message that we're not serious, said one EU diplomat anonymously, that damages the credibility of both the war crimes tribunal and the EU itself.
There is strong support within the EU for Croatian membership, but this issue needs to be resolved before further progress can be made.
On Wednesday, the United Nations chief prosecutor, Carla Del Ponte, told the EU that Croatia was still not fully co-operating with the tribunal.
She said Gen Gotovina was still at large but was within the reach of the Croatian authorities.