By Michael Martina and Simon Lewis

WASHINGTON, Feb 4 (Reuters) – U.S. Vice President JD Vance on Wednesday unveiled plans to ​marshal allies into a preferential trade bloc for critical ‌minerals, proposing coordinated price floors as Washington escalates efforts to loosen China’s grip on ‌materials crucial to advanced manufacturing.

The Washington meeting comes after President Donald Trump on Monday launched a strategic stockpile of critical minerals, called Project Vault, backed by $10 billion in seed funding from the U.S. Export-Import ⁠Bank and $2 billion in ‌private funding.

China has wielded its chokehold on the processing of many minerals as geo-economic leverage, at times ‍curbing exports, suppressing prices and undercutting other countries’ ability to diversify sources of the materials used to make semiconductors, electric vehicles and advanced weapons.

“We ​want to eliminate that problem of people flooding into our ‌markets with cheap critical minerals to undercut our domestic manufacturers,” Vance told the gathering of visiting ministers in Washington without mentioning China.

“We will establish reference prices for critical minerals at each stage of production, pricing that reflects real-world fair market value, and for members ⁠of the preferential zone, these reference ​prices will operate as a floor maintained ​through adjustable tariffs to uphold pricing integrity,” Vance said.

Shares of minerals companies fell on the news. MP Materials ‍lost 2.8%, Critical Metals ⁠dropped 7.7%, NioCorp Developments was down 2.8%, and USA Rare Earths lost 6.6% in morning trading in New York.

(Reporting by ⁠Michael Martina, Simon Lewis, David Brunnstrom, Jarrett Renshaw in Washington, Julia Payne in ‌Brussels and Robbie Corey-Boulet in Dakar; Editing by Humeyra ‌Pamuk, Deepa Babington and Mark Porter)