The order, issued last October by the Centers for Disease Control and Prevention (CDC), mandated testing and some additional safeguards for crew members as part of a framework for a phased resumption of cruises.
On Monday (25 October), the CDC extended the CSO for cruises until 15 January 2022 over concerns about the spread of the Delta variant of Covid-19.
The public health agency said the extension includes minor changes and when the order is lifted it will shift to a voluntary programme.
Clia said the update "underscores the importance of ongoing dialogue and collaboration between government and industry" as the order enters its final phase.