Pusic, who on Wednesday visited the eastern city of Pozega, said that the conflict between the Croatian Democratic Union (HDZ) and the Social Democratic Party (SDP) "is irrelevant and it is their own business".
She appealed to leaders of the ruling HDZ and the strongest opposition SDP to stop arguing for the sake of the country's efforts to join the EU.
Pusic said that it was unacceptable to use the topic of Croatia's EU membership bid for political wrangling.
"Croatia's biggest success since it gained independence is the consensus on Croatia's aspirations to become a part of Europe," she said.
Pusic does not believe that it is impossible for Croatia to make fast headway and enter the EU soon.
According to her, Croatia can prepare itself for EU membership just like Romania and Bulgaria.