(Reuters) -Shares of rare earths miners rose in morning trade on Thursday after China tightened export controls on metals crucial to the weapons and electronics industries, aiming to limit shipments to overseas defense firms and semiconductor users.

The announcement follows U.S. lawmakers' call for broader bans on the export of chipmaking equipment to China and expands on sweeping controls Beijing announced in April, which had caused shortages around the world.

The U.S. government has been ramping up its efforts to reduce reliance on China by investing in companies it considers essential to national security, including critical minerals and semiconductor companies.

Shares of Critical Metals surged nearly 18% to $13.86 and Ramaco Resources ( METCB ) surged 11%.

Shares of NioCorp Developments ( NB ) gained 5.5%, while Trilogy Metals ( TMQ ), MP Materials ( MP ) and USA Rare Earth ( USAR ) rose over 4%.

The VanEck Rare Earth and Strategic Metals ETF ( REMX ) rose 1%. It has surged nearly 91% so far this year.

China produces over 90% of the world's processed rare earths and rare earth magnets, while the U.S. has only one rare earths mine.

"The message is clear," said Neha Mukherjee, a research manager at Benchmark Mineral Intelligence. "If the U.S. and its allies want supply chain security, they must build independent value chains from mine to magnet."

Mukherjee expects more efforts towards reducing reliance on China, with increased investments and U.S. government support for developing a mine-to-magnet supply chain, along with more agreements and collaborations.

"This presents a window of opportunity for emerging producers and processors outside China to position themselves as credible alternatives," Mukherjee added.