Russia is buying millions of artillery shells and rockets from North Korea, according to newly declassified American intelligence — a sign that global sanctions have severely restricted Russian supply chains and forced Moscow to turn to pariah states for military supplies.

The disclosure comes days after Russia received initial shipments of Iranian-made drones, some of which American officials said had mechanical problems. U.S. government officials said Russia’s decision to turn to Iran, and now North Korea, was a sign that sanctions and export controls imposed by the United States and Europe were hurting Moscow’s ability to obtain supplies for its army.

The United States provided few details from the declassified intelligence about the exact weaponry, timing or size of the shipment, and there is no way yet to independently verify the sale. A U.S. official said that, beyond short-range rockets and artillery shells, Russia was expected to try to purchase additional North Korean equipment going forward.