Kosovo lawmakers backed a resolution on Wednesday condemning the 1995 Srebrenica genocide in Bosnia, a move expected to anger former foe Serbia.
Serb forces killed more than 8,000 Muslim men and boys after they captured the eastern town on July 11, 1995, in the final stages of Bosnia's 1990s war.
It was the worst massacre on European soil since World War II and was deemed genocide by international judges.
But for most ethnic Serbs and their leaders in both Bosnia and Serbia, which has apologised over the crime, the word genocide remains unacceptable.
The parliament in the ethnic Albanian-majority Kosovo "strongly condemns" the Srebrenica genocide of Bosnian Muslims, said the resolution, marking 26 years since the atrocity.
It was backed by 89 deputies of those present in the 120-seat assembly.
But, in a sign of protest, 10 Serb MPs left the session when the debate started.
The document, proposed by Bosnian MPs, also strongly condemned "any tendency to deliberately and publicly deny the Srebrenica genocide" and called on the government to declare July 11 the Srebrenica memorial day.
Albanians in Kosovo "also experienced barbaric crimes by the Serbian regime during the war", said MP Saranada Bogujevci, adding that they understood the suffering of Bosnian Muslims.
She survived a 1999 massacre by Serb forces in the northern town of Podujevo during Kosovo's war with Serb forces that ended with NATO bombing Belgrade.
During the debate, Prime Minister Albin Kurti said his government had "carefully started the preparations" to file a genocide lawsuit against Serbia for crimes committed by Serb forces during the 1998-1999 war.
Kosovo is not a UN member so cannot bring cases to the UN's International Court of Justice.
Kurti did not elaborate on where the case would be brought.
The war between independence-seeking ethnic Albanian guerrillas and Serbian forces claimed 13,000 lives, mainly Kosovo Albanians.
Kosovo declared independence from Serbia in 2008, but Belgrade still does not recognise the move.