US regulators have moved a step closer toward approving Lithium Americas Corp's Nevada mine for the white metal, launching a review process that could result in final permits to build by 2021.

The step comes as US politicians have been pushing for increased domestic mining of specialised minerals. Lithium is used to make lithium-ion batteries for electric vehicles. Albemarle is the only current US producer of lithium.

The U.S. Department of the Interior filed paperwork to ask for public comment over the next year on the Thacker Pass project's environmental impact statement, according to a post on a government website dated Jan. 21. The post appeared to be filed automatically as the department was closed on Monday for a holiday.

The 12-month review process "is a major accomplishment milestone for developing Thacker Pass," said Jon Evans, who became the company's chief executive last year.

The company plans to develop the Nevada mine, which would extract lithium from a clay deposit, in two phases over roughly 40 years. The project's footprint would be about 18,000 acres (73 square kms), according to regulatory filings.

Thacker Pass is expected to employ about 300 people when operational and produce several types of lithium. It could eventually make solid-state lithium batteries, according to the filing.

Lithium Americas plans to spend $400 million on the first phase of the project and produce 20 000 t of lithium annually.

The company hopes to begin building the mine in 2021, close it in 2061 and spend at least five years reclaiming the site, a process designed to return it as close as possible to its pre-mine state, according to the filings.

Vancouver-based Lithium Americas is also developing a lithium brine project in northern Argentina with China's Ganfeng Lithium Co Ltd, its largest shareholder.

The Nevada permit progress comes as a nearby rival has come under increased scrutiny from environmentalists.

The Center for Biological Diversity (CBD) sued US regulators last year for granting ioneer exploration permits in Nevada, arguing that ioneer's lithium project would disturb a flower.

The CBD withdrew its suit earlier this month after ioneer agreed to take additional measures to avoid the plant, but the environmental group has vowed to stop ioneer's facility from opening if any flowers are harmed.

Lithium America's project could potentially impact streams where the Lahontan cutthroat trout live, according to filings, so regulators have said they will solicit public feedback on that point over the next year.