The U.S. Environmental Protection Agency is halting plans to withdraw proposed restrictions on mining activity near a major Alaska salmon fishery.

Last year, the EPA agreed to initiate a process for withdrawing restrictions proposed during the Obama administration. It was part of a settlement with the Pebble Limited Partnership, which wants to build a copper and gold mine in Alaska's Bristol Bay region.

But in a release Friday, EPA Administrator Scott Pruitt says based on comments the agency received, he believes any mining projects in the region likely pose a risk to the natural resources there.

He says until the "full extent" of the risk is known, those resources "deserve the utmost protection."

Pebble's CEO says his company thinks it can build a mine that meets "high environmental standards."