The ambassador was quoted by the Belgrade-based Blic daily as saying on Wednesday that Croatia's entry into the European bloc was creating the necessary dynamic for the Union's enlargement to include other countries in the region, including Serbia.
Kupresak said that upon entering the EU, Croatia would lobby for the European path of Serbia.
He dismissed fears that Zagreb could block the prospective membership negotiations between Serbia and Brussels in the way Slovenia did during Croatia's accession negotiations.
"This fear is groundless as Croatia's key interest is to improve the relations between the two countries, including offering the support to Serbia in its European integration processes," the diplomat said referring to some speculation in the Serbian media that Croatia could hinder Serbia's EU membership bid due to the unsolved border issue.