After President Joe Biden announced last week that his administration is authorizing the release of another 15 million barrels from the Strategic Petroleum Reserve, Saudi Arabia’s energy minister criticized such moves and warned that “losing emergency stock may become painful in the months to come.”

During an investor conference on Tuesday, Prince Abdulaziz bin Salman spoke generally about the dangers countries face by depleting their emergency oil stocks, AFP reported. While the prince did not specifically name Biden, his criticism comes amid oil-related tensions between the U.S. and Saudi Arabia.

“People are depleting their emergency stocks, had depleted it, used it as a mechanism to manipulate markets while its profound purpose was to mitigate shortage of supply,” the prince said.

“However, it is my profound duty to make it clear to the world that losing emergency stock may become painful in the months to come,” he added.