WASHINGTON – A Colorado School of Mines professor cautioned a Senate committee Tuesday that the United States needs to extract more of its own rare earth minerals to meet an increasing demand for clean energy technologies.

Top among them is the nation’s gradual switch to electric vehicles.

“Minerals and metals are central to the energy transition,” Morgan D. Bazilian said in his testimony. “But the economic, security and geostrategic implications are all in play, depending how the U.S. policy responds.”

Bazilian is director of the Payne Institute for Public Policy at the Colorado School of Mines in Golden.

He testified before the Senate Energy and Natural Resources Committee as it considers legislation that creates incentives for U.S. mining companies to extract more of the minerals to make rechargeable batteries, solar panels, wind turbines and consumer products.

Manufacturing them often requires use of minerals such as lithium, cobalt and yttrium.

Most rare earth minerals used in the United States come from China, where regulatory and environmental obstacles are less stringent and costly. Minerals commonly are extracted from open pit mines that are unlikely to win permits from U.S. regulatory agencies.

Nevertheless, new clean energy technologies cannot do without them, Bazilian said.

“The future energy system will be far more mineral- and metal-intensive than it is today,” he said in his Senate testimony. “Many of these advanced technologies require minerals and metals with particular properties that have few to no current substitutes.”

U.S. Geological Survey studies show large rare metal deposits in Colorado, particularly in the Wet Mountains and San Juan Mountains.

A leading legislative proposal in Congress to encourage more U.S. development of rare earth minerals is the American Mineral and Security Act, S. 1317.

It would require the Interior Department to maintain a list of minerals critical to U.S. economic prosperity and national security. Regulatory agencies also would be charged with improving processes to find, develop and use the minerals for industry.

Bazilian hinted at economic benefits from greater emphasis on U.S. rare earth mineral development when he said, “The opportunity for the mining industry is tremendous.”

The National Renewable Energy Laboratory in Golden uses some of the minerals for its clean energy projects.

Concerns about U.S. dependence on foreign suppliers have grown as the Trump administration embarked on a trade war with China.

President Donald Trump signed an executive order in 2017 requiring a study of strategic minerals as he seeks a way to wean the United States off a dependence on China.

“This dependency of the United States on foreign sources creates a strategic vulnerability,” the executive order stated.

The Chinese government has responded to Trump’s trade war by considering economic reprisals, such as reducing rare earth exports to the United States and restricting foreign investment in its mining industry.

Congress has demonstrated bipartisan support for more U.S. rare earth mineral production.

“China is consolidating control of the entire supply chain for clean technologies,” said Senator Lisa Murkowski, the Alaska Republican who chairs the Energy and Natural Resources Committee.

Senator Catherine Cortez Masto, a Nevada Democrat, said, “If we don’t start embracing this technology and growing with it, we are going to be left behind.”

Nevada is the nation’s largest mining state, particularly for the kind of copper used in solar panels.

Senator Joe Manchin, a West Virginia Democrat, agreed more U.S. mining of rare earth minerals is needed but said it needed to be done “responsibly.”

Colorado Republican Senator Cory Gardner is a member of the Energy and Natural Resources Committee but he did not speak during the hearing Tuesday.