Brussels - Turkey must make sure it protects the freedom of the press, the head of the European Union's executive told Turkish President Abdullah Gul on Thursday.

"Full respect of press freedom is an important value for us. It is important that there be full respect of this basic, fundamental right," European Commission President Jose Manuel Barroso said as he welcomed Gul on the first-ever visit to the EU's headquarters by a Turkish head of state.

In particular, Barroso said that he had raised the case of Turkey's biggest media mogul, Aydin Dogan, following accusations that the Turkish government has used its powers in an attempt to stop critical press reports.

Angry at allegations of government corruption, Prime Minister Recep Tayyip Erdogan has asked supporters to boycott Dogan newspapers.

Last month the Dogan Group was slapped with an almost half-billion-dollar fine for allegedly unpaid taxes, a fine that Dogan-run newspapers decried as a direct government attack on press freedom. The fine is being appealed.

"We fully respect sovereignty on those matters regarding tax issues; at the same time, I expressed our concern regarding any decision that could put in question the necessary pluralism and complete freedom of the press," Barroso said.

However, he praised Turkey for its recent decision to open a 24-hour TV channel in the Kurdish language, calling it a "great initiative" and a "great signal of Turkey's commitment to the principles of dialogue and diversity."

And he hailed the country for its recent move to appoint a chief negotiator for EU accession talks and to approve a national plan for adopting EU laws.

Those reforms and Gul's visit "show a very encouraging commitment" from Turkey to EU accession, he said.

Gul said that his conversation with Barroso, which lasted an hour longer than planned, had been "a very comprehensive meeting in a family atmosphere."

Turkey has been negotiating on accession to the EU since 2005.

While Gul said that there are still "many things that need to be done," he also stressed that "the work is going on seriously."

The most important thing is "that the leadership of a country and the opposition, the (European) commission and the (EU) member states all remain loyal to the process," he said.

That is a challenge to EU states such as France, which oppose the idea of Turkey's joining the bloc.