Washington's drive to make the United States a major global lithium producer is being held back by a confusing mix of state regulations that are deterring developers and hampering efforts to break China's control of the critical minerals sector.

Across Texas, Louisiana and other mineral-rich states, it's unclear who owns the millions of metric tons of lithium locked in brines underneath U.S. soils, how the battery metal should be valued by regulators and who ultimately should pay to process it into a form usable by manufacturers.

These legal ambiguities are the latest impediment — alongside technical challenges and sagging commodity prices — to America's plans to produce more of its own lithium and wean the country off foreign supplies, according to interviews with regulators from seven U.S. states, legal experts, politicians, landowners, investors, royalty firms, industry executives and consultants.