The National Retail Federation (NRF) has urged labour and management to keep the ports open in Los Angeles and Long Beach following the rejection of a labour contract.

A dispute between the International Longshore and Warehouse Union's Local 63 Office Clerical Unit and the Harbor Employers Association led to most terminals at the Ports of Los Angeles and Long Beach being closed for eight days.

Following the strike, the parties agreed a tentative new contract with the help of a federal mediator, but union members voted down the contract.

"We are extremely disappointed by this vo  te and strongly urge the parties to work through their differences without any kind of disruption," said NRF VP for supply chain and customs policy Jonathan Gold.

"Ratification of a contract is needed to give retailers and other industries that rely on these ports the predictability they need to make long-term plans and get back to growing their businesses and creating jobs.

"The shut down during the holiday shopping season was more than just a fight between labour and management - it threatened to impact consumers' shopping plans at the most crucial time of the year. We can't afford to see another shut down.

"As labour and management work to resolve this situation, uninterrupted operation of the ports should be their top priority. Too many jobs across the country depend on these ports to let any interference with operations be considered an acceptable way of doing business."