US retail giant Walmart is understood to be cutting around 1,000 corporate jobs by the end of the month amid a shake-up of its workforce and just days after announcing the closure of some Sam's Club stores.

The retailer is expected to focus largely on employees in its corporate headquarters, according to a Wall Street Journal report. Bloomberg reported Walmart is planning to remove around 3,500 store co-managers and add 1,700 assistant store managers who typically earn a lower salary.

A spokesperson for Walmart said the company has been looking at its structure for some time as it explores ways to operate more effectively.

"We continue to do that but are not going to comment on rumours and speculation," the spokesperson said.

The reports follow just days after Walmart said it would close around 63 Sam's Clubs stores across the country.

The decision, the retailer said, was taken after a thorough performance review and is part of the group's plans to transform its business, which has involved looking at its real estate portfolio and invest in technology to compete more effectively against the likes of e-commerce giant Amazon.

Wal-Mart to shutter 63 Sam's Club stores