Nike reported 80 per cent of its factories in southern Vietnam were closed because of government-ordered lockdowns.
'Through this week we've already lost 10 weeks of production, and that gap will continue until factories are able to reopen and produce products at normal capacity,' said Nike CEO John Donahoe.
'This has created a gap in the flow of inventory originally ordered for delivery beginning in mid-October.' said Mr Donahoe.
The downturn in the Vietnamese manufacturing worsened through August due to Covid cases reaching the highest amount since the pandemic began.
Said IHS Markit economics director Andrew Harker: 'Vietnamese manufacturers are facing a near-impossible task because of Covid restrictions.'
The manufacturing hub of Ho Chi Minh City has been under Vietnamese army control since August 23 with only limited groups allowed out.
The areas affected by lockdown measures include Ho Chi Minh City, Binh Duong, and Dong Nai, with 25 per cent of the textile and garment factories in the country shut down.