It was the third successive year that the panel of independent experts found that all parties had violated international law.
Last week, some non-lawyer Israeli officials were predicting the ICC decision would come down before an expected Israeli annexation decision on July 1.
War crimes allegations against the KLA first surfaced in the 2011 Council of Europe rights agency report that accused guerrillas of killing civilian Serbs and ethnic Albanian political opponents.
From 2001 to 2009, Livni served in the cabinets of Ariel Sharon and Ehud Olmert and, as foreign minister, she led multiple rounds of peace talks with the Palestinians.
Former Sudanese President Omar al-Bashir is also wanted by the ICC. He faces charges of genocide, war crimes and crimes against humanity for atrocities committed by pro-government forces in Darfur.
The ICC chief prosecutor's statement came in response to a May 27 request from the ICC Pretrial Chamber to clarify the status of the Oslo Accords and their impact on the war crimes probe.
Rwandan genocide suspect Felicien Kabuga, who is accused of funding militias that massacred about 800,000 people, was arrested on Saturday near Paris after 26 years on the run.
Decision brings alleged Israeli war crimes battle closer
The country holds that the ICC does not have the jurisdiction to hear such cases.
The three ICC judges are the same exact three judges that ruled against Israel in a Comoros case relating to the 2010 'Mavi Maramara' flotilla.