Jan 31 (Reuters) - The U.S. Environmental Protection Agency's (EPA) decision to block the proposed Pebble copper and gold mining project near Alaska's ecologically sensitive Bristol Bay watershed is "unlawful" and hurts the state, said the top boss of the mining project.

The EPA has moved to prevent the company from storing mine waste at the watershed, home to important salmon species, including the world's largest sockeye salmon fisheries, which have supported critical wildlife and a multibillion-dollar industry.

"This preemptive action against Pebble is not supported legally, technically, or environmentally," said John Shively, chief executive of Pebble LP, a unit of Northern Dynasty Minerals Ltd.

He also said U.S. President Joe Biden's strategy to secure minerals for green energy goals seems to be giving "passing support" to minerals such as lithium in the United States and seeking an "enormous supply of copper ... from other nations".

The project has been on a roller coaster for the past 15 years. Former U.S. President Barack Obama opposed the project, and his successor Donald Trump ultimately also did after deciding it was too risky.

Earlier in December, the regional EPA head suggested that the agency veto the project, which has one of the world's largest copper and gold deposits.

The EPA was not immediately available for comment. (Reporting by Sourasis Bose in Bengaluru; Editing by Anil D'Silva)