Milanovic: Serbia relations 'difficult' but necessary
23 May 2013 Last updated at 14:32 BST
On 1 July 2013, Croatia will become the 28th member of the European Union.
The country's prime minister, Zoran Milanovic, has said he wants a positive relationship with Serbia and wants to see the country follow Croatia into the EU.
In the 1990s the two countries experienced ethnic violence and war.
Asked about feelings between the two countries now, Mr Milanovic told Stephen Sackur that despite finding it "difficult" to work with the Serbian government, he wanted to build a relationship in "good faith".
You can watch the full interview on BBC World News on Thursday 23 May at 2030 GMT and on the BBC News Channel on Monday Tuesday 27 May at 0430 GMT.