NATO said in a statement on Friday that it had “authorized additional forces to address the current situation” in Kosovo.
NATO did not immediately specify how many additional forces or from which countries.
A battle between police and armed Serbs holed up in a monastery turned a quiet village in northern Kosovo into a war zone earlier this week.
Kosovo, which declared independence from Serbia in 2008 after a guerrilla uprising and 1999 NATO intervention, accuses Serbia of arming and supporting the Serb fighters.
Serbia, which has not recognised its former province’s independence, blames Kosovo for precipitating violence by mistreating ethnic Serb residents. Serbia and the main Serb political group in Kosovo have proclaimed public mourning for the Serbs killed in the battle.