The three officials paid tribute to all who had given their lives for the independent and sovereign Croatia, emphasising that there would not have been a free Croatia without their sacrifice.
President Mesic said that in early 1992 Croatia had been engaged in two kinds of struggles, one for the country's survival and independence and the other for finding its niche in the world.
Both struggles were difficult and Croatia succeeded in winning both of them paying a high price, the head of state added.
That's why it is not unimportant what the present-day Croatia looks like because of those who were killed, wounded and expelled during the war. We have to build a Croatia they would be proud of, the president explained.
Croatian Prime Minister Ivo Sanader said that the state leadership in the early 1990s led by the first Croatian President Franjo Tudjman recognised historical trends in Europe and took an opportunity to realise the centuries-old dream of the Croatian people about independence and statehood.
"A democratic revolution in Europe 15 years ago made it possible for us to get independence. We did not miss the opportunity. Today, the united Europe offers peace, freedom, equality, progress and prosperity. We must not and we shall not miss this opportunity," the premier said.
The three state officials agree that 15 years ago Croatia embarked on a road towards the family of the free world, which is why Croatia's integration with the European Union and NATO is a historic responsibility of the present-day generation.
"The international recognition of Croatia in 1992 meant the recognition of its independence. Our admission to the family of the free world where we together with EU and NATO members will share the same values and fruits of permanent peace and prosperity will complete this most important cycle in the modern history of Croatia," Sanader said.
He reiterated that the current Croatian leadership was confident in the final results of those integrating processes.
"My government will succeed and we shall complete this job," Sanader stressed.
Mesic added that Croatia's EU membership "is within reach" and it is now up to Croatia to ensure the swift accomplishment of this objective.
The state authorities are also bound to inform people in a transparent and correct way about EU and NATO memberships, Mesic said adding that this would change the dissatisfaction of a majority of citizens with the integration processes.
Mesic added that Croatia should also admit its mistakes from the past.
Mesic reiterated that wrongs from the period of ownership transformation and privatisation should be redressed and that production and job creation should be now in focus.
On behalf of the 12 European countries that recognised Croatia on 15 January 1992, Greek Prime Minister Kostas Karamanlis addressed the special session.
The visiting Greek official commended Croatia for significant progress in democracy and prosperity of its citizens and for its contribution to peace and stability in southeastern Europe.
He said Greece backed Croatia's efforts to join the European Union and to successful completion of accession negotiations.