Moscow, Tbilisi, Georgia - US Secretary of State Condoleezza Rice called Thursday for an end to "violence" in Georgia's rebel regions reprimanded Russia Thursday for escalating tension with the south Caucasus state.

"We are anxious over steps taken by Russia that do not promote the peace process," she said in Tblisi, after meeting with Georgian President Mikheil Saakasvili, the Interfax news agency reported.

"The violence needs to stop," she said, adding that "Russia should contribute to resolving the problem."

Potential conflict between Tbilisi and its Russian-backed separatist regions of South Ossetia and Abkhazia has set off alarm bells in Washington, which counts Georgia as a key ally in the region.

A series of bombings that killed four people and injured dozens last week gave a grim edge to recent wranglings between Tbilisi and Moscow.

"We give as a high priority to peace settlement of conflicts in Georgia," Rice said on Wednesday, promising US mediation in resolving the frozen conflict.

But heavy warnings from Russia and sharp sallies by Rice as she began her visit Wednesday belied a longstanding battle for influence in the strategic region, to which Georgia's separatist regions threaten to become a proxy.

"I'm going to visit a friend and I don't expect much comment about the United States going to visit a friend," she shot back in response to Moscow's criticism of US support for Saakashvili.

Rice also clearly reaffirmed US backing for Georgia's bid to join NATO, a proposal that many see as having sparked the recent escalations in the Caucasus region as Russia manifests its objections to any eastward enlargement of the alliance.

Russia strengthened diplomatic ties with rebel provinces South Ossetia and Abkhazia, where most residents have been offered citizenship, following NATO's promise to remain open to Georgia's candidacy.

Abkhaz leader Sergey Bagapsh on Thursday paid a not-uncommon visit to Moscow to discuss setting up bilateral government ties with Moscow, Georgian news agencies reported.

Tbilisi has protested such steps as a de facto annexation of its territory. (dpa)