BEIJING/WASHINGTON (Reuters) -China has granted temporary export licenses to rare-earth suppliers of the top three U.S. automakers, two sources familiar with the matter said, as supply chain disruptions begin to surface from Beijing's export curbs on those materials.

At least some of the licenses are valid for six months, the two sources said, declining to be named because the information is not public. It was not immediately clear what quantity or items are covered by the approval or whether the move signals China is preparing to ease the rare-earths licensing process, which industry groups say is cumbersome and has created a supply bottleneck.

China's decision in April to restrict exports of a wide range of rare earths and related magnets has tripped up the supply chains central to automakers, aerospace manufacturers, semiconductor companies and military contractors around the world.

China's dominance of the critical mineral industry, key to the green energy transition, is increasingly viewed as a key point of leverage for Beijing in its trade war with U.S. President Donald Trump. China produces around 90% of the world's rare earths, and auto industry representatives have warned of increasing threats to production due to their dependency on it for those parts.

Suppliers of three big U.S. automakers, General Motors ( GM ),, Ford and Jeep-maker Stellantis ( STLA ) got clearance for some rare earth export licenses on Monday, one of the two sources said.

GM and Ford each declined to comment. Stellantis ( STLA ) said it is working with suppliers "to ensure an efficient licensing process" and that so far the company has been able to "address immediate production concerns without major disruptions."

China's Ministry of Commerce did not immediately respond to a faxed request for comment.  

China's critical-mineral export controls have become a focus on Trump's criticism of Beijing, which he says has violated the truce reached last month to roll back tariffs and trade restrictions.

On Thursday, Trump and Chinese President Xi Jinping had a lengthy phone call to iron out trade differences. Trump said in social-media post that "there should no longer be any questions respecting the complexity of Rare Earth products." Both sides said teams will meet again soon.

U.S. auto companies are already feeling the impact of the restrictions. Ford shut down production of its Explorer SUV at its Chicago plant for a week in May because of a rare-earth shortage, the company said.

The approval for the auto suppliers follows a green light granted to a U.S. electronics firm's suppliers last week and another one issued earlier this week to suppliers of a U.S. non-auto company, the first person said, declining to name the companies.

"We have to give the Chinese the benefit of the doubt that they're working through this. It's up to them to show that they are not weaponizing it," said the person. 

Reuters reported on Wednesday that China has introduced a tracking system for its rare earth magnet sector in a move to improve its control over the sector and crackdown on smuggling.