It follows the release of a rare earth strategy two weeks ago to reduce the US' vulnerability to supply disruptions, as attention recently turned to China's dominance of supply as trade tensions between the two countries continue.

The ERG initiative is being led by the US State Department and Bureau of Energy and Resources and aims to engage other countries on "responsible minerals governance", support resilient supply chains and meet the expected demand for clean energy technologies.

"Demand for critical energy minerals could increase almost 1,000% by 2050, straining the capacity of many countries to increase supply," the State Department said in a fact sheet on the initiative.

"Over 80% of the global supply chain of rare earth elements, important minerals for electric vehicles and wind turbine components, is controlled by one country.

"Other minerals have similar supply constraints. Reliance on any one source increases the risk of supply disruptions."

Meanwhile, China has reportedly started a survey of rare earth resources this week in seven districts including Inner Mongolia and Sichuan province.

It comes as China saw a 16% monthly drop in rare earth exports in May due to an increased focus on conserving domestic resources and high-quality development of commodities, local media reported.