Asda has set out plans to trial same-day grocery deliveries, chief executive Roger Burnley told 1,200 store and depot managers in the wake of the prohibition of the proposed takeover by Sainsbury's.
The Leeds-based supermarket chain Asda was purchased by Walmart back in July 1999 for 6.7 billion pounds.
The recent merger talks between Asda and its domestic U.K. rival Sainsbury were blocked in April this year by the U.K. Competition and Markets Authority.
McKenna said: "Walmart does not have a one size fits all approach to operating its global markets, but a consistent focus on strong local businesses powered by Walmart".
Walmart, often described as the world's largest retailer, has already listed its Mexico operations and has been buying smaller companies, such as online shopping Jet.com, as well as brands such as Bonobos and Bare Necessities, to expand into new areas.
Trade union GMB called for assurances for staff and said it had asked for an urgent meeting with Walmart bosses.
Burnley also confirmed Asda would "accelerate our price position", briefing staff on plans to invest £80 million ($103.3 million) in the price throughout the rest of 2019.
She added that any preparations for IPO would "take years" and that colleagues' primary focus should remain on delivering its strategy to "make you the best Asda you can be".
A "scan and go" initiative was launched in 25 stores last week and more "click and collect" towers will be installed in stores.