SYDNEY - Western countries could achieve an acceptable level of rare earths diversification away from China within three to five years, France's top envoy for strategic metals said on Wednesday.

Governments and manufacturers are racing to diversify supplies of metals vital to defence, technology and renewable energy and reduce dependence on China which accounts for as much as 90% of production of some specialised rare earth magnets.

Beijing rattled global markets last year when export curbs on permanent magnets disrupted industries, including the automotive sector, exposing their reliance on a single source.

Some investors and analysts have questioned whether breaking China's dominance is achievable, given the scale of investment and technical know-how required to produce the niche metals used in everything from cars and aircraft to electronics and weapons systems.

"You don't need hundreds of rare earths mines around the world to cover the supply. It's a limited market, it's a limited quantity. We have already made some progress," said Benjamin Gallezot, France's Interministerial Delegate for Strategic Minerals and Metals Supply.

Expansion projects led by Belgium's Solvay and France's Carester, plus others in Australia, the US, Japan, Brazil, and India are developing quickly, he said.

"If you take all together, these projects, and you push to accelerate them, hopefully you can have a good diversification in the next three to five years," he said, speaking on the sidelines of a mining conference in Sydney.

While rare earths mines and refining projects were progressing, the amount of magnet manufacturing could still be a limiting factor, he said.

"You don't need a decade to solve this problem."

Leaders of the Group of Seven nations agreed in June to step up coordination to cut their countries' reliance on China for critical minerals.

They aim to reduce dependence on any one supplier outside the G7 and its partner countries for rare earths and permanent magnets to below 60% by 2030, with an ultimate goal of 50% "as soon as possible".

"We can do much more," Gallezot said.