Chinese perspective: https://www.scmp.com/economy/global-economy/article/3299918/us-port-fee-proposals-targeting-china-make-waves-shipping-sector

USTR has proposed punitive port entry fees on Chinese shipping vessels, Chinese shipping companies, and non-Chinese shipping companies who use Chinese ships.

Of course, these fees may be reduced for companies which use US-built shipping vessels. Unfortunately, the US builds <5 large ocean-going ships annually, while China builds more than 1,000 such vessels each year, comprising 55.7% of world shipbuilding, so switching over in time to avoid these costs is practically impossible.

Shipping companies are already saying that they will pass these fees as surcharges to US importers and exporters.

If these policies go through, they will dramatically increase costs for US imports and exports (because ships that come into port with imports leave with US exports). This will appear as inflation for US consumers.