The memorial plaque in Otočec Ob Krki was unveiled by the two countries' current prime ministers, Janez Janša and Plenković, and their prime ministers of 30 years ago, Franjo Gregurić of Croatia and Alojz Peterle of Slovenia.
"We remember all the horrors that happened during the Great Serbian aggression of the Milošević regime, and the crucial role in it of the then Yugoslav People's Army (JNA), both in Slovenia and in Croatia," said Plenković.
As of mid-1991 there were no longer JNA troops in Slovenia's territory, while a part of Croatia's territory was occupied until 1995 and the military and police operations Flash and Storm, Janša said.
"We suffered the consequences of that aggression practically throughout the 1990s, and the scars and traces of that period and Slobodan Milošević's insane policy are unfortunately felt to this day," Plenković added.
Janša said that "it is important to have a good neighbour in difficult situations" and that Croatia and Slovenia were good neighbours to one another at the time.
Gregurić said that understanding and cooperation made it possible for businesses to reopen despite the war, for trade to function as well as transport, "which to us was very important because there were de facto major barriers to transport connectivity due to the war in Croatia, not only with Serbia but the Eastern Bloc as well."
"Our customs and police services agreed very quickly and there were no impediments to the transport of any goods and services between Croatia and Slovenia. To us it was very important to have free passage and a corridor to the West," the former Croatian PM said, thanking Slovenia for taking in a portion of Croatian refugees, and Plenković and Janša for their successful cooperation.
Slovenia's six-month EU presidency is nearing the end and Slovenia has been a partner to Croatia on its journey to accession to the Schengen and euro areas, said Plenković.
"Slovenia has been not only a friend and partner that supports us, it has been an EU chair actively helping us make progress in the months to come," Plenković said.