For his part, Rasim Ljajic, Serbian minister for cooperation with the UN's Hague tribunal, judged the "pressure" imposed on his country as having negative consequences.

"This will practically strengthen the anti-European political structures [in the country]", he was quoted as saying by Serbian news website B92.

The International Crime Tribunal for former Yugoslavia's (ICTY) prosecutor Carla Del Ponte said on Monday (15 October) that Belgrade's cooperation with the tribunal had improved, but was still "slow, without results, irresolute".

In addition, she said she was "convinced" Serbia had the means to arrest the remaining fugitives wanted by the ICTY, notably Bosnian Serb general Ratko Mladic indicted for war crimes and genocide.

Serbia, on the other hand, had been expecting a much more positive report, taking into account its efforts – the latest one being a reward of €1 million offered by the authorities for information leading to the capture of Mr Mladic.

Following Ms Del Ponte's assessment, the EU decided to postpone its decision on initialling a Stabilisation and Association (SAA) agreement with Serbia, which it wants to launch only if Belgrade is cooperating fully with the tribunal.

It will now wait for an update after the prosecutor's next trip to Belgrade at the end of this month.

Cedomir Jovanovic, president of the Serbian Liberal Democratic Party – an opposition party in Serbia – told journalists in Brussels he was "disappointed because our government did not finish the cooperation with The Hague".

But on the other hand, "without an EU perspective the anti-Hague lobby [in Serbia] will be the winner and our society – victims", he said insisting on the need for closer EU-Serbia relations.

Slovenian liberal MEP Jelko Kacin, the European parliament's rapporteur on Serbia, said that despite the fact that the most wanted general is still at large, "there is evident progress and we have to strengthen the pro-European spirit in Serbia".

He added that cooperation with the ICTY should not be the one and only factor when EU-Serbia relations are assessed.

"We hope that the future development in Serbia will not be focused just on cooperation with The Hague. We believe that there are other areas where we desperately need a progress".

For example, more has to be done "to improve the social life of people", he said in Brussels on Tuesday.

MEPs are to debate and vote on a progress report on Serbia during their plenary in Strasbourg next week.