Member states of the OSCE on Thursday battled to achieve a compromise on an action plan that would bolster the clout of the trans-Atlantic security group after its first summit in over a decade.

"I hope that in the remaining moments we can agree a declaration and overcome the differences," Kazakh President Nursultan Nazarbayev told the final session of the OSCE summit in Astana.

"I am counting on your flexibility. History has given us a unique chance and it would be unforgivable to lose it."

"We still have a job to be finished. We need to show that we can have a consensus," added Lithuanian President Dalia Grybauskaite, whose country will hold the chairmanship next year.

"Time will tell if we can deliver today and finish with something real achieved, not just a nice meeting, lunch and dinner," she added.

Leaders including US Secretary of State Hillary Clinton and Russian President Dmitry Medvedev had the day earlier urged a revamp of the Organization for Security and Cooperation in Europe to better cope with modern security threats.

The last such summit dates back to a 1999 meeting in Istanbul.

However Russian Foreign Minister Sergei Lavrov said that Moscow would not accept any document containing a reference to an ongoing "conflict" in Georgia or an insistence on the country's territorial integrity, AFP reported.