The European Union's counterterrorism chief says member states need to have common laws against Europeans traveling to Syria and Iraq to join jihadist groups.

At the moment the 28 members of the bloc have different definitions of what constitutes terrorism, with some banning individuals from traveling to join extremist groups and others only prohibiting them taking part in terrorist activities.

Gilles de Kerchove told reporters in Riga on Friday that "it's important to have the same definition of what is it when you go abroad for training purposes to fight."

He said each EU nation has to make sure it has adequate laws "to investigate, prosecute and convict terrorists. Instead of having 28 different definitions, we should have one single one."