The European Union has issued an ultimatum for social network giant Facebook to explain how the US-based firm would deal with the aftermath of a recent scandal that involved the loss of private data of its users.

In a Tuesday letter addressed to Facebook’s chief operating officer Sheryl Sandberg, EU’s justice commissioner Vera Jourova gave the company two weeks to answer questions about the harvest of personal data by British firm Cambridge Analytica, which played a role in US President Donald Trump’s election campaign.

Jourova asked Facebook what plans the firm has to prevent a similar scandal in the future.

“Have any data of EU citizens been affected by the recent scandal? If this is the case, how do you intend to inform the authorities and users about it?” Jourova asked in the letter.

The EU official also asked Facebook if there was a need for stricter rules in regulating the social media platforms and how such regulations could affect the Facebook’s own transparency vis-à-vis users and authorities.

 Jourova set a deadline for Facebook to answer the questions.

“I would appreciate a reply in the next two weeks,” he said in the letter.

The Facebook scandal dominated an EU summit in Brussels last week. Leaders of the 28-nation bloc issued a statement at the end of the summit, urging more efforts to protect data and privacy of users.

“Social networks and digital platforms need to guarantee transparent practices and full protection of citizens’ privacy and personal data,” said the statement, adding, “EU and national legislation must be respected and enforced.”

In their statement, EU leaders also vowed to further discuss the issue of data privacy in an upcoming summit in the Bulgarian capital Sofia in May.