"The tone of her speech will be marked by the need for new unity, the same kind of unity on which (first Croatian president) Franjo Tudjman built the Croatian state," Mladen Pavic told reporters following a dress rehearsal for the presidential inauguration.
He added that the inaugural speech of Croatia's first woman president would not be critical, but positive and optimistic.
"She will send a strong message of new unity in the world and Europe against the backdrop of current developments. She will state a need and wish and her initiative for young people to stay in Croatia, for a fresh start in Croatia."
Grabar Kitarovic will also send a message to all neighbours about the need to continue good neighbourly relations and cooperation in dealing with outstanding issues, Pavic said.
The record 88 delegations to attend the inauguration will include a Ukrainian delegation, and Pavic said that the fact Ukrainian President Petro Poroshenko wanted to attend the event, considering the situation in his country, spoke for itself.
After the inauguration, a formal dinner will be organised for senior foreign officials and on that occasion Grabar Kitarovic will hold 22 bilateral meetings, including with Serbian Prime Minister Aleksandar Vucic.
Pavic said this would "definitely be a message of openness, a message that finally something big can be achieved in relations between the two neighbouring countries."
"I believe the opportunity will be used to at least touch on some of the issues that have persisted for a long time and to at least announce the continuation of dialogue so that those issues are resolved as soon as possible," he said.