Sanctions could be imposed by the United States on mainland tonnage if Beijing introduces mandatory tariff filing.
A Lloyd's List report quoted Harold Creel, chairman of the Federal Maritime Commission (FMC), as saying vessels faced US port bans, detention, or fines, unless the mainland modified regulations for the 'registration of international sea freight container bills of lading and filing of sea freight rates'.
Mr Creel said retaliatory action was possible if the dispute was not resolved.
The FMC had discussed the matter with the mainland authorities, who were fully aware of the potential risks, Mr Creel said.
Further talks are being conducted by the US State Department and the Maritime Administration. Mr Creel said sanctions would be 'the last straw'.
Mr Creel said Beijing's move to regulate liner shipping was inconsistent with trend elsewhere in the world towards deregulation.