Serbia's foreign minister has urged the United Nations Security Council to oppose the province of Kosovo's expected declaration of independence.
The US and many EU countries plan to recognise Kosovo's independence
Vuk Jeremic said Serbia would not use force to stop the secession but warned that allowing it would give a green light to other separatist movements.
The ethnic Albanian majority in Kosovo is expected to announce its breakaway from Serbia within days.
Russia has warned that recognition of Kosovo would be illegal and immoral.
Speaking after the closed session, Serbia's foreign minister said that is was not too late for diplomats to prevent Kosovo's unilateral declaration of independence.
He called on the Security Council to continue to negotiate, and he claimed that a majority of member states agreed that the search for a compromise should continue.
But Mr Jeremic also warned that independence for Kosovo would set a precedent across the world, leading to "an uncontrolled cascade of secession".
Earlier on Thursday, at an international news conference, Russian President Vladimir Putin dismissed claims that Kosovo was a "special case".
He argued that Kosovo was in the same category as the separatist conflicts in parts of the former Soviet Union, such as Abkhazia, South Ossetia and Trans-Dniester.
He said Russia - a permanent member of the UN Security Council and traditional ally of Serbia - has "a ready-made plan and we know what we are going to do".
The BBC's Matt Wells at the UN headquarters says Security Council members France, Britain and the US are just as firm in their view that Kosovo should make up its own mind, and that individual member states should decide whether or not to support an independent Kosovo.
As far as they are concerned, the UN has no real role left to play, although the UN mission will remain in Kosovo for the foreseeable future, our correspondent says.
The United Nations has administered Kosovo since a Nato bombing campaign in 1999 drove out Serb forces accused of persecuting the province's majority ethnic Albanians.
A civilian police and justice mission for Kosovo is expected to be given the go-ahead by EU member states by the end of the week.
A senior official told the BBC's Oana Lungescu in Brussels that deployment of the 1,800 staff would be staggered over four months.
By early June, 1,500 police officers including special anti-riot units and 250 judges, prosecutors and customs officials would be in place to maintain stability in the self-proclaimed state.
The police and judges are expected to come from Germany and Italy as well as other countries, including the United States, Turkey, Croatia, Norway and Switzerland.