Whole Foods Market chairman and chief executive John Mackey has mounted a robust defence of the performance of its debut UK store in London.

Speaking on a conference call with analysts, the Whole Foods co-founder responded to a question about expansion in the UK, given speculation that its store on Kensington High Street is underperforming.

Mackey said: “We’re not going to comment on rumours, but Kensington remains the top 10 store for us in terms of sales, so we’re very pleased with the sales of the store – it’s being executed at a very high level.”

He promised it would deliver its maiden profit in about 12 months. “We did invest quite a bit in the store, so it’s probably going to be a year or so before we can make a profit. But we’re pleased with the results of the store from a sales and operating standpoint.”

Whole Foods Market executive vice-president for growth and business development Jim Sud said: “We continue to be aggressive in our approach to the UK and committed to the UK. We recently hired a new vice-president of real estate [Nina Shores], who just started in January – a person who lives in London to oversee our real estate activities over there.”

Sud added: “And so, in just the first few weeks that she’s been in the job, she’s really started to turn up a number of opportunities for us, which is good news as far as we’re concerned. So we’re hoping that we’re going to see more opportunities in the future to open stores in the UK and remain committed to it.”