China dominates the global industry for extracting and refining rare earth minerals but since April has required licences to export some of the materials, triggering jitters among businesses worldwide.

"Our economy needs robust and resilient supply chains -- this is especially true for key technologies of the energy transition such as wind turbines," said the German economy ministry, as it released the roadmap drawn up with five European wind power industry groups.

The roadmap relates specifically to magnets made from rare earths, which the ministry said are "key to reliable and economical power generation, especially in the offshore sector".

The plan aims to ensure that 30 percent of such magnets are sourced from outside China by 2030, rising to 50 percent by 2035, through steps such as promoting closer ties with "friendly countries" like Australia and Japan.

Besides wind turbines, rare earths are used in a wide variety of products ranging from electric car batteries to hard drives.

At a recent EU-China summit, Beijing agreed to speed up exports of the minerals to the bloc.

Germany aims to have renewables make up 80 percent of its electricity supplies by 2030, and is aiming to triple its current offshore wind power capacity by that date.

Particularly since Russia's invasion of Ukraine stoked fears about economic reliance on authoritarian states, Berlin has been seeking to reduce its dependence on China.

For its part, China has urged Germany to ensure fair treatment for Chinese businesses.

Several attempted investments by Chinese firms in Germany have been blocked or scaled back on national security concerns.