Chinese rare earth magnet producers have faced stricter scrutiny on export license applications since September, according to multiple industry sources, even before Beijing’s latest expansion of controls on the critical minerals used in magnets.

The lengthier review process has raised concerns that China — the world’s dominant supplier of rare earth magnets — may be quietly curbing exports despite pledging to expedite shipments as part of its trade truce with the U.S. in May. Analysts say the move could signal Beijing’s intent to strengthen its leverage over materials vital to both military and commercial technologies.

Two sources familiar with the matter said export license applications have increasingly been returned for supplementary information, while approvals, though still generally within the Commerce Ministry’s 45-business-day window, are taking longer. The heightened scrutiny mirrors conditions seen in April at the peak of the trade war, when prolonged licensing delays triggered magnet shortages and forced temporary shutdowns at several automotive plants.