Dockworkers have threatened to strike on Oct. 1 in major ports on the East Coast and Gulf of Mexico, which could complicate trade and lead to a disruption in the flow of goods in North America.

The International Longshoremen’s Association union has threatened to strike if it does not reach a new labor agreement by Sept. 30. The union represents 45,000 workers at 36 ports, including New York, New Jersey, Houston, and Savannah.