ANKARA (Reuters) - Turkey has met the required criteria to secure visa-free travel for its citizens to Europe, but the European Union says it has not yet met stipulations on personal data and terrorism, Turkey's EU minister said on Thursday.

Omer Celik, flanked by Turkish Foreign Minister Mevlut Cavusoglu, made the comments to reporters in Brussels ahead of talks to "open" Chapter 33 of its European Union accession process, which covers budget policy.

Cavusoglu told CNN Turk that it was important for Turkey to retain momentum in EU talks. Turkey won visa-free travel for its citizens to Europe in return for agreeing to curb the flow of migrants to the bloc. However, sticking points have remained over Turkey's anti-terror laws, which some in Europe see as too broad.

The opening of Chapter 33 marks a modest step forward in Ankara's accession process to Europe.

(Reporting by Tulay Karadeniz and Seda Sezer; Writing by David Dolan; Editing by Daren Butler)