Walmart warned of a tough Christmas shopping season for US retailers as it forecast weak sales amid the most intense competition it had ever seen.
Despite improvements in the US economy, the world's biggest retailer by sales blamed the jobs market, political gridlock in Washington and the end of some food stamp benefits for its tepid forecast.
It also reported a third consecutive quarter of falling US sales on Thursday.
Bill Simon, head of Walmart's US business, said that a "once in a generation" set of forces were discouraging consumer spending. People will also have less time to shop as a late Thanksgiving means there are six fewer days to Christmas than last year.