Russia and Georgia have reached an agreement on how to prevent security incidents in or around the breakaway South Ossetia region where they fought a brief war last year, an EU mediator said on Wednesday.

The agreement is the first since the two countries launched a series of confidence-building talks in October under international mediation.

"We consider that the proposals agreed by consensus are an important stage in contributing to stability and security," Pierre Morel, special representative of the European Union, told a news conference.

He was speaking after the fourth round of talks on security and humanitarian issues hosted at the U.N.'s European headquarters in Geneva by the EU, United Nations and Organisation for Security and Cooperation in Europe (OSCE).

The United States, which sees Georgia as an ally in the Caucasus, also sent a senior envoy to the talks.

Morel said there had been agreement on setting up a mechanism to prevent incidents or settle them if they arose.

Both sides -- including representatives of all the forces on the ground -- would meet weekly or more often if necessary to discuss possible incidents that could undermine security. They would be joined by representatives of the three mediators, and also have a hotline.

Participants in the talks had not yet set a date for their next meeting, but had agreed that they would discuss security arrangements such as the non-use of force and international presence in the region, Morel said.

Russia sent troops into its small, ex-Soviet neighbour after Georgian government forces launched an assault on South Ossetia, which had thrown off Georgian rule in 1991-92.

Last week the U.N. Security Council extended the mandate of U.N. ceasefire observers in another breakaway Georgian region -- Abkhazia -- for four months in the hope that Russia and Georgia would reach a political deal soon.

The mission has been in place since Moscow-backed Abkhazia threw off Tbilisi's control in 1993, but was called into question after last year's brief war over South Ossetia.

The talks have been bedevilled by differences over the status of representatives from the breakaway regions, which Tbilisi insists are still part of Georgia, while Moscow has recognised them as independent states.