The UN security council has failed for a second time to reach an agreement on a call for an immediate halt to the conflict in Georgia's breakaway region of South Ossetia.

The 15-member council met on Friday but were unable to find a form of words to use in the statement urging a ceasefire between Georgian troops and separatist forces backed by the Russian military.

"Some members need more time," Jan Grauls, the envoy for Belgium, which chairs the council this month, told reporters.

"Negotiations will be resumed tomorrow."

The security council will reconvene on Saturday.

Friday's emergency session in New York was dominated by the Russian and Georgian envoys hurling accusations at each other.

'Scorched earth'

Vitaly Churkin, Russia's ambassador, said Georgia was deliberately targeting Russian peacekeepers in South Ossetia and accused Tbilisi of "ethnic cleansing".

"Tbilisi is using a tactic of scorched earth. A number of towns in South Ossetia have been fully destroyed according to some reports," he said.

"Georgian snipers are not letting through ambulances, not allowing the medical services to get on with saving people."

Irakli Alasania, Georgia's envoy to the UN, rejected Churkin's charges and accused the Moscow of aggression.

"Russia is openly challenging the international community and jeopardising established international order and stability," he said.

"We demand the Russian Federation immediately terminate aerial bombardments, immediately pull out the occupying forces, and negotiate ceasefire," he said, adding that Saakashvili was ready for direct peace talks with the Russians.

Towards the end of the meeting, he turned directly to Churkin, and asked, "Are you ready to stop the fighter jets who are in the air who will soon be bombing my comrades in Georgia, and what will the security council do about this now? How are we going to address this?"

He received no reply.

Ceasefire calls

Although the UN was unable to agree to urge an end to the heavy fighting, which officials in South Ossetia said had killed at least 1,400 people, several nations have already made such a call.

Zalmay Khalilzad, the US ambassador to the UN, reiterated the US position that Russia should withdraw its troops from the conflict zones and halt all attacks on Georgia.

"We deplore the Russian military action in Georgia, which is a violation of Georgian sovereignty and territorial integrity," he told reporters after the meeting.

Karen Pierce, Britain's ambassador to the UN, said, "I'd also like to take the opportunity to reiterate calls for a ceasefire, for withdrawals, and we look to the Georgians, the Russians, the South Ossetians and other fighters to desist from violence."

On Thursday, the security council had failed to reach an agreement at a first emergency session. 

Diplomats said that a phrase calling on all sides "to renounce the use of force" was unacceptable to the Georgians, who were supported by the US and the Europeans.