Sen. Tom Cotton (R-AR) on Tuesday urged the Trump administration to review its military equipment shipping policy in the wake of concerns that U.S. fighter jet parts were lost in China, making him the most senior Republican so far to weigh in on the debacle.

Cotton, who chairs the Senate Intelligence Committee, wrote a letter to Defense Secretary Pete Hegseth outlining concerns after a shipment of fighter jet parts appeared to have been lost to the United States’ most powerful rival. F-35 stealth fighter components from Australia that were bound for the U.S. for repairs ended up being rerouted in transit over the summer and were eventually lost after arriving in Hong Kong.