The UN Security Council will meet Thursday behind closed doors at the request of Serbia and Russia, the council's president Panama's UN Ambassador Ricardo Alberto Arias said.

"The council agreed that the meeting shall be held as a private debate and the Serbian foreign minister will be invited to participate. Representatives of Kosovo were not invited," he said.

In a letter sent to the council president on Tuesday, Serbia urged to consider the grave situation in Kosovo where a unilateral declaration of independence is expected soon. Russia supported the Serbian request, the UN news center said.

In Belgrade, media have speculated Serbia would recall ambassadors and cut off diplomatic relations with various countries that recognize Kosovo's independence.

The Serbian government has only said it will "annul" the proclamation, and has threatened to take legal action against countries that recognize Kosovo.

But its traditional ally Moscow was not planning any punitive measures in response to the move, said Russian Foreign Minister Sergei Lavrov.

"Russia does not have among its political instruments any measures for punishing anyone" but was convinced unilateral independence "would be a mistake," Lavrov said in Slovenia after meeting with senior EU officials.