The moratorium, which came just days after U.S. President Barack Obama said he would push for a change in the way coal and oil resources in the country are managed, will stay in place until officials examine whether fees charged to mining companies provide a fair return to taxpayers and reflect coal's impact on the environment.

"Given serious concerns raised about the federal coal program, we're taking the prudent step to hit pause on approving significant new leases so that decisions about those leases can benefit from the recommendations that come out of the review," Interior Secretary Sally Jewell said, in a statement released Friday. "We haven't undertaken a comprehensive review of the program in more than 30 years, and we have an obligation to current and future generations to ensure the federal coal program delivers a fair return to American taxpayers and takes into account its impacts on climate change."

However, the moratorium does not apply to existing coal production activities, the mining of metallurgical coal — which is used to make steel — and emergency leasing, the statement clarified.