U.S. President Donald Trump said on Friday that Chinese President Xi Jinping had agreed to restart the flow of rare earth minerals and magnets to the United States.

But there was a discrepancy in the two sides’ statements after the Trump-Xi call on one of the most contentious issues: rare earths, which are needed to make all kinds of advanced technologies and are produced almost entirely in China.

Mr. Trump said in a post on Truth Social that his call with Xi Jinping, China’s top leader, had focused entirely on the trade relationship between the nations, which has soured in recent months in a dispute over the export of critical minerals used in an array of industries.