The US military asked mining companies last Friday to help boost domestic supplies of 13 critical minerals used to ​make semiconductors, weapons and other products, a document reviewed by Reuters showed.

The request, the day before the US and Israel launched strikes on Iran, ‌is the latest example of Washington's push for more access to the materials used widely in warfare.

The Pentagon asked members of the Defense Industrial Base Consortium (DIBC), a group of more than 1 500 companies, universities and others that supply the military, for proposals to be submitted by March 20 for projects that could mine, process or recycle select minerals, the document showed.

While the DIBC has ​worked on minerals-related issues for some time, there was no immediate indication as to whether the timing was intentionally coordinated to coincide with the start of ​the strikes on Iran.

The list of 13 minerals sought includes arsenic, bismuth, gadolinium, germanium, graphite, hafnium, nickel, samarium, tungsten, vanadium, ⁠ytterbium, yttrium and zirconium.

The US is reliant on imports for most of the 13. China is a dominant global producer of all of them.

DIBC member Guardian Metal Resources plans ​to apply for funding for its two tungsten projects in Nevada, said J.T. Starzecki, the company's executive chairman. Tungsten is used to harden steel and China is ​the world's largest producer.

"This is the opportunity we've been waiting for," Starzecki told Reuters. "Our plan is to look for an application that would give us a funding package to allow us to get to full production at both sites."

American Tungsten, which is developing an Idaho mine for that metal, plans to apply for funding next week that would complement a loan it has ​applied for from the US Export-Import Bank, said CEO Ali Haji.

The Pentagon asked for detailed information on the costs, including labor and material, needed to build ​a mine or processing facility. Projects could be awarded development funds ranging from $100-million to over $500-million, according to the request.

The document did not specify why only those 13 minerals were ‌chosen. Some — ⁠including germanium, graphite and yttrium — have been subject to export restrictions by China, the top global producer.

Yttrium shortages, especially, have set off alarm bells throughout the aerospace industry. One of the 17 rare earths, yttrium is used in coatings that keep engines and turbines from melting at high temperatures. Without regular application of these coatings, engines cannot be used.

Colorado-based Energy Fuels, also a DIBC member, said it is developing facilities to process gadolinium and samarium by 2027, and is considering processing yttrium.

"The domestic supply ​of critical minerals remains essential to safeguarding ​both national security and economic stability," ⁠said Mark Chalmers, the Energy Fuels CEO.

Nickel is a widely traded metal and Indonesia is the top global producer. Yet Jakarta has been throttling exports of the metal used widely in stainless steel and battery production.