(Recasts with Serbian, European Commission reaction) By Mark John and Patrick McLoughlin RIGA, Nov 29 (Reuters) - NATO offered Serbia, Bosnia and Montenegro on Tuesday a first step towards membership despite unresolved war crimes concerns, in a policy switch cheered by the region but condemned by the top U.N. prosecutor. The 26-member alliance had, like the European Union, until now required Serbia and Bosnia to show full cooperation with the Hague war crimes tribunal on tracking down top indictees still at large before winning closer ties. But, after a summit in Riga, NATO leaders declared: "Taking into account the long term stability in the Western Balkans and acknowledging the progress made so far by Bosnia and Herzegovina, Montenegro and Serbia, we have today invited these countries to join Partnership for Peace." Diplomats said the invitation was made after a change of heart by the United States, Britain and the Netherlands, who had been among those taking the strictest line on Serbia. Carla del Ponte, chief prosecutor at the International Criminal Tribunal on the former Yugoslavia (ICTY), attacked the NATO decision as a reward for non-compliance."The prosecutor is very surprised by the decision. She regrets that it was made, that NATO changed its position because it looks like a reward for not fully cooperating with the prosecutor," her spokesman said in The Hague. Serbian President Boris Tadic called the step "great news for the citizens, the army and the state". Bosnia's Prime Minister Adnan Terzic said NATO sent "a message to the region that our insistence on Euro-Atlantic integration will pay off". Serbian Prime Minister Vojislav Kostunica went further, saying the invitation showed the Western policy of imposing conditions on Belgrade for closer ties was wrong. "Lately one could see favourable winds from several countries pointing out that Serbia should be encouraged in the process of European integration and the process should not be conditioned," Kostunica told reporters. NO CHANGE TO EU LINE Partnership for Peace sets out a programme of NATO help for partners in revamping their armies and other defence reforms. The EU suspended talks with Serbia on a Stabilisation and Association Agreement (SAA) in May for failing to arrest former Bosnian Serb military commander Ratko Mladic, wanted on genocide charges over the 1995 Srebrenica massacre in the Bosnian war. In a statement, the EU's executive Commission said it believed the NATO move was reward for "reform of their military sector and encourages further reforms in a delicate area which is critical also to improving their ICTY cooperation". But a Commission source said: "Each organisation has set its own conditionality for different stages in the relationship. For the EU, it is clear that for Serbia to resume SAA negotiations, full cooperation with the ICTY is the condition." The Netherlands, which had U.N. peacekeepers in Srebrenica at the time of the massacre and hosts the war crimes court, dropped its objection at the last minute after winning assurances of strict monitoring. "We'll keep up the pressure," NATO Secretary-General Jaap de Hoop Scheffer told a news conference. The NATO leaders also welcomed reform efforts in Albania, Croatia and Macedonia and said those that met alliance criteria could expect to receive invitations to join at a 2008 summit. The summit declared support for membership efforts of Georgia and Ukraine, but without promising to accept them. Ukraine's pro-Moscow prime minister has recently contradicted its pro-Western president on the need to join NATO. (Additional reporting by Ellie Tzortzi in Belgrade)
