S&P Global has released a new analysis through the World Shipping Council, highlighting the liner shipping industry's vital role in the U.S. economy, as Washington prepares to implement port fees on Chinese vessels, prompting strong warnings from the industry.

The report independently quantifies the annual impact of the liner shipping industry across key metrics including, GDP contribution, employment, wages, sales activity, and government revenues.

The report found that liner shipping (both container and vehicle carriers) contribute over US$1.1 trillion to U.S. GDP and supports 6.4 million jobs.

It also handles 64.4% of U.S. seaborne trade by value, making it the dominant mode of ocean transport for American imports and exports.

The report said liner shipping transports nearly US$1.5 trillion in U.S. trade annually, including US$335 billion in exports and US$1.1 trillion in imports, and generates US$262.5 billion in U.S. federal and state tax revenue.

"The report also emphasizes liner shipping's essential role in U.S. domestic production. 44% of U.S. imports transported by liner ships, valued at US$490 billion, are industrial inputs such as components, supplies, and raw materials used by American businesses," it said, adding that these inputs generated US$628 billion in additional U.S. economic output.

S&P noted in the report that liner shipping makes over 18,000 port calls across the US, underscoring the industry's central role in maintaining reliable trade flows and resilient supply chains.