Chinese president Xi Jinping on Monday visited a major rare-earth minerals company in Jiangxi province, Xinhua News Agency reported. It triggers speculations that the country could stop exporting rare-earth to the US amid an escalating trade war.

Xi’s visit came soon after the US government “blacklisted” Huawei and threatened to cut it off from the US software and semiconductors it needs to make its products.

China is the world’s largest producer and exporter of rare earth minerals and the US relies on China for about 80% of its rare earths imports, making it a potential bargaining chip for China in trade talks.

In response to inquiries about the intention of the visit, foreign affairs ministry spokesman Lu Kang said one should not “over-interpret” the move as “it’s only normal for the Chinese leader to pay a domestic visit and study relevant industrial policy.”

Rare earth minerals were among the few items excluded from the latest US government plans to implement tariffs on almost all of China’s exports to the US, highlighting its strategic importance.