The Minister for Defence, Senator the Hon Linda Reynolds CSC, will take a period of medical leave.
This follows advice from her cardiologist relating to a pre-existing medical condition.
As a precautionary measure, Minister Reynolds has this morning been admitted to a Canberra Hospital.
The Prime Minister, the Hon Scott Morrison, this morning phoned Minister Reynolds to express his concern and sympathy, and to wish her a quick recovery.
The Minister for Foreign Affairs, Senator the Hon Marise Payne, will be acting Minister for Defence until Minister Reynolds returns from leave.