The completion of the negotiations depends on when Croatia will complete key reforms, Barroso said, adding that Brussels expected concrete results from Zagreb.

There are many benchmarks to be met, particularly for closing the policy area "Judiciary and Fundamental Rights", he said.

The head of the EU executive arm said that Croatia's EU entry talks were in the final stage and their completion "is within reach", but he stopped short of mentioning any date.

You are now in the final stage of your path to the EU membership. This is the most difficult stage, preparations are a difficult job. European citizens must know that your country is completely ready when it enters (the Union), he told Croatian MPs.

I have come to encourage you in the final stage of the negotiations and congratulate you on impressive efforts, but those efforts must be finalised, he said.

Commenting on his meeting with Prime Minister Jadranka Kosor earlier in the day, he said that they had agreed that it was necessary more than ever to keep the present momentum in the talks, notably on "Judiciary and Fundamental Rights", which included the strengthening of the fight against corruption, prosecution of war crimes and respect for minorities' rights.

Barroso reiterated in his speech that it was most important for Croatia to be ready for full EU membership in order to be able to use the membership benefits.

Being a part of the biggest single market with 500 million residents and using common funds are the greatest benefits of EU membership, he said, adding that one should prepare to make the best of those advantages.

Describing Croatia's prospective admission to the Union as a "catalyst" for this region, the EC president said that the Western Balkans' European prospects remained high on the EU agenda and that his tour of the region, which he started by visiting Zagreb, reaffirmed the Union's commitment to this historical goal.

After the speech in the Sabor, Barroso went sightseeing in the centre of Zagreb and met with representatives of civil society organisations in a cafe in the main square.