A handshake between Kosovan prime minister Hashim Thaci and former Serbian president Boris Tadic has triggered outrage in both countries.
The two attended a summit of current and former regional leaders and EU officials in Dubrovnik, Croatia.
It was the first time the two had met face-to-face since the 1998-99 war between Serb government forces and independence-seeking Kosovo Albanians that left thousands dead and millions homeless.
Mr Thaci, a former ethnic Albanian guerrilla commander, and Mr Tadic, who lost a May presidential election against nationalist opponent Tomislav Nikolic, shook hands during the summit, but apparently held no official talks.
Serbia, backed by Russia, has refused to recognise the independence of its former province.