The Presidency of the 25-country Bloc congratulated the International Criminal Tribunal for the former Yugoslavia and the Spanish and Croatian authorities on their work in bringing about this important arrest.
"The Presidency is convinced that this arrest marks an important milestone for Croatia and for the region. It also demonstrates the success of the EU's policy of insisting the countries of the Western Balkans fully cooperate with the tribunal," the UK presidency of the EU said in a statement.
"The arrest and transfer of all indicted persons who repeatedly evade international justice remain of the highest importance for the EU," the Presidency said, calling upon the Serbian and Bosnian authorities to locate and transfer Karadzic and Mladic to The Hague without delay.
The Croatian general, who had been at large since 2001, was arrested in the night between Wednesday and Thursday in the Canaries by the Spanish police. He was transferred to Madrid on a military plane on Thursday under high security measures where he appeared before a court of first instance which, according to the Spanish media, will transfer him to The Hague without an extradition procedure.
The German government also hailed the arrest of the top Croatian fugitive, German Foreign Minister Frank -Walter Steinmeier said on Thursday evening.