The General Data Protection Regulation could complicate a proposed merger of WhatsApp, Facebook and Instagram's messaging services in the European Union.

The Irish Data Protection Commission said on Monday Facebook's plan to integrate all messaging services owned by the company “can only occur in the EU if it is capable of meeting all of the requirements of the GDPR.”

GDPR violations can be costly. Last week, fellow tech company Google was hit with a $57 million fine from France's data privacy enforcement agency, Commission nationale de l'informatique et des libertés, or CNIL.

Menlo Park, California-based Facebook's proposed messaging merger was first reported Friday by The New York Times. Facebook, Instagram and WhatsApp would still operate from individual apps, but users could send cross-platform messages, connecting more than 2 billion users. In a statement, the company said that “there is a lot of discussion and debate as we begin the long process of figuring out all the details of how this will work.”

“While we understand that Facebook's proposal to integrate the Facebook, WhatsApp and Instagram platforms is at a very early conceptual stage of development, the Irish DPC has asked Facebook Ireland for an urgent briefing on what is being proposed,” the Irish DPC said in a press release Monday. “The Irish DPC will be very closely scrutinising Facebook's plans as they develop, particularly insofar as they involve the sharing and merging of personal data between different Facebook companies.”

The Irish DPC is responsible for upholding EU data privacy laws in Ireland, where Facebook's European headquarters are located.

Facebook is currently under a separate Irish DPC investigation. In October, the commission began examining Facebook's GDPR compliance, particularly the company's obligation to adequately protect user data. Facebook announced on Sept. 28 that a breach of its platform impacted up to 50 million users, fewer than 10 percent of whom are EU residents.

“Previous proposals to share data between Facebook companies have given rise to significant data protection concerns and the Irish DPC will be seeking early assurances that all such concerns will be fully taken into account by Facebook in further developing this proposal,” the commission said.

Read More: