"On the first shift today, the ILWU refused to dispatch any longshore workers to container terminals, the PMA said, resulting in the shutdown of the port.

The ILWU, however, said that the West Coast ports are open and accused the PMA of "leveraging one-sided information to influence the process."

“Despite what you are hearing from PMA, West Coast ports are open as we continue to work under our expired collective bargaining agreement,” said ILWU International President Willie Adams, Reuters reported.

Unions are seeking a pay increase that reflects workers' contribution to the ocean shipping industry's record profits from the pandemic cargo boom. They also want added compensation for the hours worked since their contract expired.

West Coast ports stretching from California to Washington state are critical to the US supply chains and the economy. More than 22,000 dockworkers at those trade gateways have been working without a contract since July.

The Port of Seattle has not yet issued an official statement in this regard.