Retailers are rushing to bring merchandise into the United States to protect against potential disruptions arising from ongoing contract talks between West Coast International Longshore and Warehouse Union and the Pacific Maritime Association.

U.S. ports currently are experiencing their highest monthly container volumes in at least five years, according to figures just released by the National Retail Federation and Hackett Associates. They reported a total of nearly 1.5 million boxes moving through the ports in June.

Talks over a new contract between the ILWU and the Pacific Maritime Association that covers nearly 20,000 workers at 29 West Coast ports have already extended past the July 1 expiration date of the old agreement, but that was expected by industry observers.

Further delay was incurred when the two sides announced this week a 72-hour break from negotiations last until today, so that the union could turn its attention to ongoing negotiations with grain-terminal operators in the Pacific Northwest. Four ILWU locals have been bargaining with the Pacific Northwest Grain Elevator Operators over a new contract for more than two years. Two operators, Mitsui-United Grain Corp. and Marubeni -Columbia Grain, have locked out union grain handlers since February and May of 2013, respectively. The previous labor agreement lapsed in September of 2012.