About 700 people were evacuated from two towns located near tailings dams operated by Vale and ArcelorMittal on mounting fears after last month's breach at Brumadinho, the country's deadliest mine disaster.
The National Mining Agency aims to issue an ordinance on Friday requiring that upstream tailings dams be taken down or converted into other types of dams.
Vale has come under intense public pressure since the Jan. 25 dam burst, with some politicians and prosecutors calling for criminal prosecution and a management shakeup.