The U.S. move to penalize China-built and China-owned vessels calling at U.S. ports could lead to an oil supertanker made in China and operated by a Chinese company facing a fee of up to $5.2 million per call at a U.S. port, shipbrokers have estimated.

The U.S. last week announced fees on vessel owners and operators of China based on net tonnage per U.S. voyage. The previous proposal was a per-port-entry fee of up to $1.5 million on Chinese-built vessels, and up to a $1 million per-port-entry fee on any vessel (Chinese-built or non-Chinese-built) for operators that have any Chinese-built vessels in their fleet or orderbook.

Now, the Office of the United States Trade Representative (USTR) plans to impose fees on operators of Chinese-built ships based on net tonnage or containers, increasing incrementally over the following years.