The social network is to start warning people when it has a "strong suspicion" that an account has been compromised by a nation-state.
Instead of simply resetting a password, Facebook warns that those affected should either "rebuild or replace" their mobile phone or computer system.
A user with a suspected compromised account will be presented with a message with the headline: "Please Secure Your Accounts Now".
The message reads: "We believe your Facebook account and your other online accounts may be the target of attacks from state-sponsored actors."
The user will then be urged to secure their account by turning on a feature called Login Approvals, which sends a one-time confirmation text to the account's registered mobile phone whenever a login is made from a new device or browser.
Facebook said the message is not an indication that Facebook itself has been hacked in any way. Instead it alerts users that their own system has been compromised.
Facebook says it will not explain how it spots whether a user has been compromised, but added: "We plan to use this warning only in situations where the evidence strongly supports our conclusion.