The move aims to reduce US reliance on China for the minerals, which are used in military and other hi-tech equipment.

The United States Department of Defense is in talks with Australia to host a facility that would process rare earth minerals, part of an effort to reduce reliance on China for the specialised materials used in military equipment, a senior American official said.

The push comes as China threatens to curb exports to the US of rare earth materials, a group of 17 minerals used in the production of fighter jets, tanks and hi-tech consumer electronics.

China is the world’s largest processor and producer of the minerals accounting for more than 80 percent of global processing capacity.

“We’re concerned about any fragility in the supply chain and especially where an adversary controls the supply,” Ellen Lord, the Pentagon’s Under Secretary of Defense for Acquisition and Sustainment, told reporters at a Washington event on Monday.

Lord said the Pentagon was looking at several options to partner on rare earth processing facilities, adding “one of the highest potential avenues is to work with Australia”.

Australian Department of Defence officials said that cooperation on critical minerals that had begun in 2018 was ongoing.

“Continuity and guarantee of supply of rare earths and critical minerals is vital to a range of sectors, including defence. Cooperation with international partners is integral to this effort,” a defence spokeswoman told Reuters.

The Pentagon update came after the US said earlier this year that it would look to Australia and Canada to develop rare earth reserves around the world to reduce the global reliance on China. It has also held talks with rare earth projects across Africa.

Lord said she has held several talks with Australian officials this year about whether such a plant could supply the Pentagon’s needs.

US President Donald Trump last month ordered the Pentagon to find better ways to procure a range of magnets made from rare earths, warning that the nation’s defence would suffer without adequate stockpiles.

Australia’s Lynas Corp is the world’s largest rare earths miner and processor outside of China and plans to have an initial processing plant running within the next four years. It is also planning to develop a rare earth separation facility in Texas following regulatory issues at its processing plant in Malaysia.

Rare earth developers in Australia are edging closer to building plants. The country contains only 2.8 percent of the world’s rare earth reserves, but accounts for more than half of the new projects in the global pipeline.

Northern Minerals, which has built a demonstration plant at its Browns Range project in Western Australia, will be ready to decide on the final form and funding of a full-scale plant in about a year, a spokesman told Reuters.

Rare earth minerals need to be processed after they are extracted from the ground. There is only one operational rare earths mine in the US, though the country has no processing facilities.

California’s Mountain Pass mine is building a processor and hopes to have it online by next year.