Russia and Georgia on Tuesday pledged to reactivate a security response mechanism aimed at calming tensions after the two sides went to war last summer over Georgia’s attempt to reclaim the Russian-backed breakaway region of South Ossetia.

International mediators said talks in Geneva on security and humanitarian issues in South Ossetia and Abkhazia, Georgia’s other secessionist region, were back on track after Abkhazia refused to participate on Monday, and South Ossetia and Russian officials walked out.