America’s biggest retailer said it plans to raise prices this month because of “unprecedented” costs stemming from Donald Trump’s tariffs.

Walmart said it will raise prices in May and early this summer, in the latest sign that Mr Trump’s recent climbdown with China will not be enough to save US households from the pain of higher inflation.

John David Rainey, Walmart’s chief financial officer, told the Wall Street Journal: “The magnitude and speed at which these prices are coming to us is somewhat unprecedented in history.”

Walmart’s share price dropped by as much as 4pc on Thursday morning.

The company has already raised the price of some goods in response to the higher tariffs, Mr Rainey said, with bananas rising from 50 cents (£0.38) per pound to 54 cents because of tariffs.

However, shoppers have yet to feel the full impact of the trade war as the new charges on imports flow through to supermarket shelves, Mr Rainey said.