The Trump Administration is reportedly warning Chinese shipping firms to have their tankers use transponders, with rising concerns that they are turning them off to evade US sanctions on Iranian crude. The Reuters news agency said it spoke with “two senior [US] administration officials” who requested anonymity. One of them was quoted as saying: “We’ve been messaging very heavily to the shipping companies, you don’t want to do this, it’s not worth it. It’s incredibly dangerous and irresponsible behavior.” Ships that turn off their transponders cannot be tracked, decreasing maritime safety. According to Reuters, after US sanctions were imposed on “five Chinese individuals and two Chinese COSCO Shipping Corp subsidiaries” for alleged violations of sanctions against Iran, “14 COSCO Shipping Tanker (Dalian) vessels… stopped sending location data….” It added that after it ran an October 9 report citing data from a vessel-tracking company, “[a]ll but three of the ships” suddenly became traceable once more. COSCO, it said, denied that any of its tankers’ transponders had been switched off.