It is absolutely a very positive step, Fuele told reporters in Brussels on Monday, adding that he appreciated it that many Croatian citizens had voted in the referendum, regardless of whether they had voted in favour or against, and that those who had turned out for the vote had paved the way for Croatia to make final steps before becoming a full member of the bloc.

When asked to comment on the low voter turnout, Fuele said that it was the Croats' own affair and that refusal to vote was a way of expressing one's opinion.

What is most important is that the Croats had a chance to vote and that two-thirds of those who turned out voted in favour of Croatia joining the EU and in favour of strengthening the EU with Croatia as a full member, he added.

Fuele said that the successful referendum had paved the way for the ratification of the accession treaty in Croatia and in the EU member states, adding that Croatia still had work to do before joining the EU on July 1, 2013, which he said would be monitored by the European Commission.

When asked if he expected any problems during the ratification process, Fuele said he did not, but noted that he thought it was not an automatic, but a very serious process.

Commenting on the fact that Croatian citizens had supported their country's entry despite the current crisis in the EU, Fuele said that the two-thirds majority was part of the answer, that enlargement was never a problem but part of a solution, and that Croatia's entry would make the EU stronger.

Fuele said that the positive outcome of the Croatian referendum was a very positive signal to Belgrade, Pristina and other capitals in the Western Balkans. I hope those countries will use the positive momentum created by the successful preparation of Croatia for EU membership, he said.

European Parliament President Martin Schulz has also welcomed the news that preliminary results show around 67% of Croatian voters voted in favour of EU membership on Sunday.

"The positive result of the referendum is a clear indicator of the continuing attractiveness of the EU. Membership is the right reward for the remarkable progress achieved by Croatia in its path to reforms in the recent years. The Croatian example sends a positive signal and an encouragement to the whole of South East Europe that when reforms are pursued, the EU responds accordingly, even if in the immediate future we need a phase of internal stabilisation," Schulz said in a statement Monday.

Croatia signed an EU accession treaty at the end of last year and will become the 28th member of the EU on 1 July 2013, after all 27 EU countries ratify the accord.