''Bulgaria needs to show its economy is more closely aligned to its wealthier EU peers before it considers joining the euro zone'', the European Central Bank's chief economist Peter Praet said on Wednesday, Reuters reported.
The Balkan country joined the European Union in 2007 and while it has relatively low inflation and stable public finances, its entry into the euro zone has been stymied by its failure to tackle high-level graft and low income levels.
"When you look at the formal, numerical convergence criteria, it looks quite good," Praet told a financial forum in Sofia.
"Of course the debate ... is always about what we call now sustained convergence, more structural. Because once you join the monetary union, it's irreversible. There is no exit," he said.