Serbian President Aleksandar Vucic kicked off an official two-day visit to Croatia — the first official meeting between the Serbian and Croatian heads of state in five years — by holding talks with his Croatian counterpart, Kolinda Grabar-Kitarovic, on February 12.

The presidents of Croatia and Serbia have pledged to intensify work on border issues, minority rights, and searching for missing persons from their 1990s war in an effort to improve strained bilateral ties.

Grabar-Kitarovic said that it was “unfortunate” that the “past is still preventing us from being able to describe the relations between our two countries as friendly.”

“It is our obligation to meet and talk and find common interests,” she said after meeting with Vucic, adding that the two countries had a “common responsibility for the future of southeast Europe.”

Vucic said he came to “discuss all our open issues, which are many.”

“In the next 100 days, we will try to change the atmosphere,” he added.

Croatia and Serbia are the two largest republics to emerge from Yugoslavia, which collapsed in 1991 and descended into a bloody war. They have sought to improve ties since, but tensions remain. Relations between the two nations are considered key for the peace and stability of the Balkans.

Vucic was also due to hold talks with Prime Minister Andrej Plenkovic and parliament speaker Gordan Jandrokovic, as well as minority Serb representatives and religious leaders during the visit.

The sides were expected to discuss minority rights, unresolved border disputes, people still missing since the war, and cooperation in the prosecution of war crimes suspects.

Safety measures were increased in Zagreb ahead of Vucic’s visit. Serbian flags could be seen in the streets where the Serbian president passed.

Hundreds of people responded to a call by war veteran groups to protest against Vucic’s trip and gathered on Zagreb’s Ban Jelacic Square yelling “For Home – Ready” (“Za Dom – Spremni” – salute used during World War II by the Croatian Ustaše movement. It was the Ustaše equivalent of the fascist or Nazi salute “Sieg heil”). Carrying Croatian flags, the protesters demanded an apology and war reparations from Serbia.

The European Union says Serbia needs to establish good neighborly relations if it wants to joins the bloc. Croatia is already an EU member.

In a message on Twitter, President Grabar-Kitarovic wrote on January 30 that she was inviting her Serbian counterpart “in good faith that both sides have a desire to overcome disputes and events which have kept us hostage to the past and to move forward to enable progress for our peoples and states.”

Confirming he had accepted the invitation, Vucic said on January 31 that his talks with Croatian officials “will not be easy or pleasant, but I am convinced that it will be useful for both Croatia and Serbia.”

Vucic initially planned a trip to Zagreb in late 2017, but indefinitely postponed it amid a spat over a statue erected in Belgrade to a soldier of the Serb-dominated Yugoslav People’s Army who blew up an ammunition depot during the Croatian war of independence in the city of Bjelovar. The soldier, Major Milan Tepic, is seen by the Croatian side as a criminal.

Croatia’s Foreign Ministry said the erection of the monument confirmed that Serbia “still isn’t ready to confront the past and its role in the bloody breakup [of Yugoslavia].”

Serbian Foreign Minister Ivica Dacic accused Croatian officials of “anti-Serbian hysteria.”

Earlier last year, relations were strained over an exhibition on the World War II death camp at Jasenovac in Croatia where tens of thousands of Serbs, Jews, Roma, and anti-fascist Croats perished. The Jasenovac concentration camp, run by Croatia’s Nazi-allied Ustase regime, was an extermination camp established in Slavonia by the authorities of the Independent State of Croatia (NDH) during World War II. The camp was established by the governing Ustaše regime and not operated by Nazi Germany. It was one of the largest concentration camps in Europe and the camp has been referred to as “the Auschwitz of the Balkans” and “the Yugoslav Auschwitz”. Dacic opened the exhibition at the United Nations headquarters in New York in January.

The meeting between Vucic and Grabar-Kitarovic will be the first official meeting of the Serbian and Croatian presidents since 2013, when Serbian President Tomislav Nikolic met Croatia’s Ivo Josipovic in Belgrade.