U.S. ports along the East and Gulf Coasts are extending delivery hours for importers as they rush to clear cargo ahead of a potential strike by dockworkers on Oct. 1.

Beth Rooney, port director of the Port Authority of New York and New Jersey, said the busiest port on the Eastern seaboard is anticipating a shutdown.

The union, which represents dockworkers across 36 ports on the U.S. East Coast and the Gulf of Mexico, threatens to strike on Oct. 1. If its members walk off the job at ports stretching from Maine to Texas,