Federica Mogherini, the EU's high representative for foreign affairs, said foreign ministers will send a "strong message" that the rule of law and the democratic system of checks and balances must be respected in Turkey in the wake of the putsch failure.
Belgian Foreign Minister Didier Reynders said Turkish authorities' reaction to the failed coup needed to be "proportionate." He said he was alarmed by the arrests of judges and calls for reinstatement of the death penalty against coup participants.
Some 8,000 police officers across Turkey have been removed following the attempted military coup.
The move comes as President Recep Tayyip Erdogan continues his "cleansing operation" after the attempt to oust him on Friday night by members of the country's military.
Over 6,000 people in the army, judiciary and other state bodies have been arrested following violent clashes in Ankara and Istanbul, where at least 290 people were killed.
Soldiers closed the bridge over the Bosphorus river in Istanbul around 10pm local time on Friday, in the first part of their plot to overthrow the country's leadership.
Tanks were then stationed outside the main Ataturk airport in the city and soldiers took over the state broadcaster - forcing the newsreader to read out a prepared statement live on air saying a "peace council" was in control.
But President Erdogan - who was on holiday at the time of the coup - gave a defiant interview over FaceTime to urge his supporters to go out onto the streets and defy the coup.
Later on Mr Erdogan was able to fly into to Istanbul and reestablish control.
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