Biden's comments on Tuesday were the clearest to date about the rubric administration officials deploy when determining whether or not to support a proposed US mining project.

It now proposes a cap of $2.4 billion in payments for repairs from the deadly dam disaster that happened in 2015.

In its latest assessment of 250 mine sites, the Responsible Mining Foundation found that that commitments are commonplace, yet basic actions are rarely evident.

Creditors are expected to vote on the latest proposals to restructure some $5-billion in financial debt.

The Canadian miner has approached smaller rival Arch Resources to gauge their interest in buying a stake of 10% or more in the business.

Company posted a 41% jump in full-year core earnings on Wednesday,

Its "de-bottlenecking plan" will increase the combined design processing capacity of the concentrator plants.

The copper, nickel and precious metals venture in Sudbury, Ontario, had its operations halted in September.