Unionized US dockworkers say they won’t unload cargo that’s bound for Canada as a show of support for port workers on strike in British Columbia.

The strike by members of the International Longshore & Warehouse Union Canada began on July 1 and has disrupted shipments of goods and commodities through Vancouver — Canada’s busiest port — and Prince Rupert. The labor action has “potentially disrupted” C$7.5 billion ($5.7 billion) in cargo and prompted at least two vessels to divert to ports on the US west coast, the British Columbia Maritime Employers Association said Monday.

Now, US dockworkers are pledging to back their Canadian counterparts. ILWU members “will not be unloading Canadian-bound cargo in solidarity with our brothers and sisters in ILWU Canada,” Willie Adams, ILWU’s international president, said in a statement emailed by the union.

A move by US dockworkers to refuse container ships that were rerouted from Vancouver would damage “the reliability and competitiveness of West Coast ports up and down the coast,” the BCMEA said in a release.

The union and the employers met with federal mediators over the weekend, according to a statement. The BCMEA put forward a revised proposal with increased benefits for casual tradespeople, increased apprenticeships and a tool allowance, the employers’ group said on Saturday.