BRUSSELS, Belgium (AP) - The United States insisted Tuesday that it will block efforts by Croatia and Serbia-Montenegro to draw closer to NATO until the Balkan nations hand over suspects to the international war crimes tribunal.
"NATO has to hold this line on these war criminals," said Undersecretary of State Nicholas Burns. "We can't forget and we cannot let these war criminals off the hook."
His comments came a week after the European Union adopted a softer line on closer ties with both countries.
Burns also gave vigorous U.S. backing to the decision Friday by U.N. Secretary-General Kofi Annan to recommend the start of international talks that could lead to the independence of Kosovo.
"It's time to begin the final status talks," Burns told reporters after talks at NATO headquarters. "It is time to give the people of Kosovo a chance to determine their own future."
He said the talks should start before the end of this year and "proceed in a rapid and focused way." Burns was noncommittal on whether Kosovo should chose independence or remain as an autonomous part of Serbia.
"It is not for us to be scripting the result and you won't hear the United States favoring either of those two alternatives," he said.
The EU last week opened membership talks with Croatia although Gen. Ante Gotovina, a fugitive wanted by the international court, remains at large.
The Europeans also started talks on a cooperation agreement with Serbia-Montenegro despite the country's failure to detain Bosnian Serb war leader Ratko Mladic.
Burns said the United States would block any effort by the 26-nation NATO to make a similar move.
"The message is very clear, Croatia will not become a member of NATO until (Gotovina) is arrested and sent to The Hague, and Serbia will not become a member of Partnership for Peace until Mladic is," he said.
Partnership for Peace is a NATO outreach program that has been used to prepare nations for membership of the alliance.
Burns took a particularly tough line on the Serb leadership in Belgrade and in the Serbian entity in Bosnia.
"We're going to have to judge the authorities in Belgrade especially, as well as the authorities in (Republika Srpska capital) Banja Luka, by their actions, because their words have just not amounted to much," he said.
Burns is scheduled to travel to Bosnia, Serbia and Kosovo after his meeting in Brussels.