Serbia's president has a strongly pro-EU agenda
The Netherlands has blocked a move to unfreeze EU trade ties with Serbia, saying Belgrade's co-operation over war crimes suspects is not yet adequate.
"The outcome will only change when I conclude there is full co-operation," said Dutch Foreign Minister Maxime Verhagen on Monday.
The blow to Serbia came despite its arrest of former Bosnian Serb wartime leader Radovan Karadzic in July.
France said a "very big majority" of EU states favoured unfreezing trade ties.
The Netherlands is demanding that Serbia co-operate fully with the UN war crimes tribunal in The Hague by capturing two remaining fugitives - former Bosnian Serb army commander Ratko Mladic and former Croatian Serb leader Goran Hadzic.
EU foreign policy chief Javier Solana said he expected all 27 EU members to agree to unblock the interim, pre-membership accord with Serbia at the foreign ministers' meeting next month.
Serbia's Deputy Prime Minister, Bozidar Djelic, condemned the Dutch position as "deeply unfair".
"It is extremely disappointing that one country, and as we have heard one man, now would have to decide on the future steps of the European integration of Serbia," Reuters news agency quoted Mr Djelic as saying.
Serbia and the EU signed a Stabilisation and Association Agreement (SAA) in April.
Mr Verhagen said UN war crimes prosecutor Serge Brammertz had briefed the EU foreign ministers on "progress" made by Serbia in its co-operation with the tribunal in The Hague.
But the case of Ratko Mladic is especially sensitive for the Netherlands, as Dutch UN peacekeepers were overpowered by his Bosnian Serb forces in Srebrenica in 1995. He is charged with genocide over the massacre of up to 8,000 Bosniak (Bosnian Muslim) men and boys from Srebrenica.