The mining company says there are several reasons for the decision, including delays and uncertainty about government environmental assessments.
Among other things, it says a judicial challenge by a number of First Nations communities has created uncertainty in the federal environmental assessment.
At the provincial level, it says there's been a delay in approving the terms of reference for Ontario's environmental assessment process.
It also cited unfinished agreements with Ontario government and unresolved issues with land surface rights.
The Ring of Fire area of the James Bay Lowlands in Northern Ontario has a major deposit of chromite, which is used to make stainless steel.
Cliffs is an international iron ore producer that wants to develop the deposit and become North America's leading supplier of chromite.
The company says it will continue to work with the provincial government and First Nations communities in an attempt to restart the work.