Along with a number of European Union leaders, primarily from Central and Eastern Europe and the Baltic, Grabar-Kitarovic attended the ceremony organised by Polish President Bronislaw Komorowski, who wanted this anniversary of victory over Nazism to take place in a city where "one of the biggest tragedies of humankind" had begun.
EU leaders thus avoided a traditional military parade in Moscow, expressing their disapproval of Russia's role in the Ukraine crisis.
Together with Grabar-Kitarovic and Polish President and host Komorowksi, the event in the Polish city on the Baltic coast was also attended by the presidents of Bulgaria, Cypress, the Czech Republic, Estonia, Lithuania, Romania and Ukraine, as well as the officials Hungary and Latvia and U.N. Secretary-General Ban Ki-moon and European Council President Donald Tusk.
Although announced, French President Francois Hollande and Germany President Joacim Gauck did not attend the event. Germany was represented by former president Horst Koehler and French defence minister Jean-Yves Le Drian.
"After WWII, Europe said never again (...) I never thought I would find myself one day in a cruel war which took place after Croatia escaped the jaws of the totalitarian regime. Twenty years after the war in Croatia and the slaughter in Srebrenica, the principles of sovereignty, territorial integrity and political independence are more important than ever before,“ the Croatian president said alluding to the situation Ukraine is currently facing.
She underlined the importance of "the culture of peace, tolerance, trust and solidarity."
"This can be achieved only through European integration," she stressed and warned that EU integration was "an unfinished job" and advocated the integration of Europe’s southeast and the Western Balkans.
"The responsibility for peace and global solidarity is on us," Grabar-Kitarovic said during a panel debate on European integration as a lesson from WWII.
Ukrainian President Petro Poroshenko drew a parallel between the 1930s and 2015, pointing out the fragility of the two periods.
"Today we must ensure that the mistakes of the 1930s must never be repeated, as a large-scale conventional conflict in Europe seems closer than ever before," he stressed, adding that Ukraine today was on the defence line of European values, justice, democracy, freedom and solidarity.
Giving up on Ukraine means giving up on these values, Poroshenko said.
"It is key to continue pressure on Russia (...) Astonishingly, again we see an attempt to appease the aggressor,“ said Poreoshenko whose speech was loudly applauded.
"Now, while Ukraine fully abides by the letter and the spirit accorded in Minsk, the aggressor mounts its military strength in Donbas, planning the parade in 2 days, which is completely against all the principles of the Minsk agreements and which will involve Russian state-of-the-art weaponry and heavy artillery in a few hundred metres from the touchline. Tomorrow on May 8th, for the first time the people of Ukraine will join the European tradition to commemorate the World War Two victims. While, the very next day in Moscow, under the pretext of the Great Victory, the aggressor's army will rattle its lethal might in front of the world. Some of the units were in Donetsk a few days ago and soon they will appear on the military parade in Moscow," Poroshenko said.
Grabar-Kitarovic and other officials paid respects to Polish soldiers on the Westerplatte peninsula.