Speaking after talks with European Union and Croatian leaders in Luxembourg, del Ponte did however voice hope for progress within weeks in finding fugitive general Ante Gotovina.

Her comments came after the EU, which delayed the start of talks with Zagreb last month, reiterated the need for "full cooperation" in finding Gotovina, and pointed to the example of neighbouring Serbia in surrendering suspects.

"The keys to the EU door are held in the hands of the Croatian authorities," said Luxembourg Foreign Minister Jean Asselborn (photo), whose country currently holds the EU's rotating presidency.

"Cooperation with the International Criminal Tribunal for ex-Yugoslavia is a clear pre-condition which is inescapable," Asselborn said. But del Ponte, chief prosecutor at the Tribunal, lamented that this was still not the case.

"The Croatian authorities are not fully co-operating with the tribunal and with the office of the prosecutor," del Ponte told journalists, adding that she believes Gotovina is in the reach of the Croatian authorities.

Cautious optimism

On a more positive note, she said "It is my great hope that this can be done ... before my next report to the Security Council," which is scheduled for June 13. She said that the Croatian Prime Minister Ivo Sanader (photo) had promised to be more active in locating Gotovina, adding that all information indicates he is still in Croatia, but moves across into Bosnia-Hercegovina from time to time.

The 25-member EU refused to start negotiations originally scheduled to get underway on March 17 because Croatia was not doing it all it could to find Gotovina.

Gotovina is charged by the ICTY over alleged war crimes against ethnic Serbs at the end of the 1991-1995 Serbo-Croatian war. Zagreb has insisted it has no knowledge of his whereabouts.

Del Ponte acknowledged the possibility that Croatian authorities do not know his every movement. "What I think is that Prime Minister Sanader probably himself doesn't receive all the information," she said.

Full co-operation

There has been some discussion over exactly what is meant by "full cooperation", but del Ponte sought to clarify the semantics on Tuesday. "There will be full cooperation when the Croatian authorities will have brought Gotovina to the Hague or when they indicate to us the whereabouts of Gotovina," she said.

British Foreign Secretary Jack Straw (photo), whose country takes over the European Union's rotating presidency from July 1, cited neighbouring Serbia as a good example of the EU's firm stance.

"We are very anxious to see Croatia start its negotiations on EU accession, but the union is clear about the need for full co-operation in the same way every other former republic in

Yugoslavia has co-operated," he said.

Slow process

He cited the EU green light given to Serbia and Montenegro this week to start talks on an association accord with the EU after the surrender of former Yugoslav army chief Nebojsa Pavkovic to the International Criminal Tribunal for ex-Yugoslavia.

"The fact that Pavkovic has given himself up to the tribunal in the Hague is proof of the importance of the firm and consistent line taken by the EU in support of the war crimes tribunal in the Hague," said Straw.

Sanader meanwhile acknowledged there was no immediate prospect of a breakthrough, saying the process could take weeks or even months.