Wal-Mart’s international sales rose 13% to $6.4bn (£3.2bn) in April, boosted by Asda.

The US retail giant, which owns Asda, said the supermarket chain had “contributed significantly” to the month.

“The Asda stores generated increased traffic and sales from customer initiatives in food and general merchandise,” it added in a sales update.

However, Wal-Mart did not fare so well in domestic markets. Like-for-like sales in its US operations fell 3.5% during April - its worst results for 28 years. It blamed the decrease on poor weather and an earlier Easter.

Meanwhile, Asda has been criticised for selling ‘size zero’ clothes in its George clothing range.

Customers have complained that the range stocks UK size four clothes, which are the equivalent to a size zero in the US.