Any preparations for going public would "take years", she said.
Asda is expected to reveal a further quarter of sales growth on Thursday but Roger Burnley, the chief executive of the retailer, has acknowledged it will be harder to sustain momentum without the Sainsbury's deal.
Asda is understood to be considering a stock exchange flotation following the collapse of its proposed merger with fellow supermarket giant Sainsbury's.
Walmart has revamped its global portfolio by selling a majority stake in its Brazilian business and acquiring a majority interest in Indian e-commerce leader Flipkart Group in its biggest-ever deal.
Mexico and the United States are close to a deal on metal tariffs
House of Representatives Speaker Nancy Pelosi to discuss plans for lawmakers to vote on the agreement. Mr Mnuchin said Wednesday this was likely to be worked out soon.
Tim Hortons Has Added Beyond Meat Breakfast Sandwiches To Its Menu
Tim Hortons' new Beyond Meat Farmers Breakfast Wrap , Breakfast Sandwich, and Vegan Sandwich. The company says it is opening the equivalent of a new restaurant every seven hours.
Boris Johnson Confirms Will Bid To Be British PM
Such a step would complete the first stage of Britain's divorce from the European Union and set it on the path she had laid out. Labour has feared any compromises on issues such as workers' rights would be torn up by May's successor.
The remarks by Ms McKenna are the first time Walmart has commented on its plans for the United Kingdom supermarket following the collapse of its deal with Sainsbury's.
The decision prompted analysts to speculate that Walmart would try to sell Asda to private equity or consider a stock market listing for the business, which it paid 6.7 billion pounds to acquire in 1999. Union leaders said they had demanded an urgent meeting with Asda's bosses to seek reassurances for staff about the future of the company.
McKenna was speaking to Asda managers at an event in Leeds on Tuesday (14).
Asda, which calls its staff "colleagues", intends to make £80m of price cuts during the rest of this year and trial new technology.
A "scan and go" initiative was launched in 25 stores last week and more "click and collect" towers will be installed in stores.