Croatia took a giant step towards European Union membership Friday, winning a green light from Brussels to join in mid-2013, a move opening a fresh page in the history of the Balkans nation.

"Today is a historic day for Croatia and the European Union," said Jose-Manuel Barroso, president of the EU executive.

"I would like to congratulate the people of Croatia," he added. "Joining the EU family of nations is first and foremost your success!"

Barroso said Croatia had successfully completed six years of tough negotiations to gain entry to the bloc and become its 28th member.

He recommended closing the final four of 35 chapters that aspiring members must negotiate in order to gain EU entry -- reforming political, economic, social and judicial spheres in line with EU standards.

"This paves the way for Croatia to join the EU as the 28th member state as of 1 July 2013," he added.

The next step will be for EU leaders to offer their official rubber stamp at a summit June 23-24.

The announcement from the EU executive comes shortly before the Balkan nation celebrates 20 years of independence from Yugoslavia and 16 years after the bloody inter-ethnic war that ensued.

Hailing the news even before it happened, Croatian President Ivo Josipovic told AFP in an interview the previous day that it would be "a big day for Croatia as it opens a new page in our history."

Croatia will be the second former Yugoslav republic to join the EU after Slovenia in 2004, but the first that suffered the full force of the brutal wars that ravaged the region in the 1990s.

Much of the negotiations in the last months stumbled over judicial reforms and Croatia's cooperation with the UN war crimes court, but Zagreb had leapt ahead even in that difficult and sensitive field, said Justice Commissioner Viviane Reding.

"The last stumbling block was the judiciary," she said. I didn't believe last year that Croatians could do it. But in one year's time they completely reformed their judiciary and made it irreversible.

"They are on track and we can give with very much calm and a good heart a yes, Croatia."

Many hope that the green light for Zagreb, six years after opening negotiations to join, will boost reconciliation in the whole Balkans region.

"I know from talks with many European leaders that they expect Croatia to serve as a bridge to help southeastern European countries become EU members," Josipovic said.

"Europe will not be complete until all southeastern European countries are in it."

Barroso too said he hoped Croatia's upcoming integration would serve as an inspiration to others in the Balkans "to reinvigorate their reform efforts and to deliver to the benefit of their people."

The government in Zagreb has touted huge financial benefits from membership, calculating that Croatia will be able to draw some 3.5 billion euros ($5 billion) from EU structural funds.

Economic experts expect entry will also boost investors' optimism, pushing growth in the country of 4.4 million whose economy is still in recession.

But many ordinary Croats do not share the enthusiasm.

Polls still show 44.6 percent support EU membership, but the opponents, on 41.8 percent, are gaining ground.

The country is due to hold a referendum within a month of the EU accession treaty being signed.