BRUSSELS, June 8 (Reuters) - EU industry chief Thierry Breton will meet Meta Platforms Chief Executive Mark Zuckerberg on June 23 and demand that he take immediate action to tackle online child-sex content as the company's voluntary child protection code seems not to be working, an EU official said on Thursday.

Breton will also warn Meta to demonstrate the measures it will take to comply with EU online content rules after Aug. 25 or face heavy sanctions, the official told Reuters. (Reporting by Foo Yun Chee)