BHP said Samarco and its lenders had yet to reach an agreement on the restructuring of its debt.
BHP Billiton Brasil Ltda. and Vale S.A. each held a 50% interest in joint venture Samarco.
BHP also stressed the restart of Samarco's operations would occur only if it was 'safe, economically viable and has the support of the community.'
Resuming operations required the granting of licences by state and federal authorities and community hearings, among other requirements, the company added.
At 8:02am: (LON:BHP) share price was -7.9p at 1611.3p