EU Justice Commissioner Didier Reynders said he shared the worries and has asked WhatsApp to clarify the policy and if it complies with EU consumer protection law.
"WhatsApp has until the end of February to come back to us with concrete commitments on how they will address our concerns," he said in a statement.
The Commission said it was also concerned about the exchange of users' personal data between WhatsApp and third parties or other Facebook/Meta companies.
"We look forward to explaining to the European Commission how we protect our users' privacy in compliance with our obligations under EU law," a WhatsApp spokesperson said.
(Reporting by Foo Yun Chee; Editing by Hugh Lawson)