Aldi plans to open a new store in the UK every week on average for the next two years, its boss has told the BBC.
Giles Hurley said the discount retailer would invest £1bn to achieve its aim.
"The reality is that almost 50% of the population of the UK doesn't currently shop with us and they tell us the main reason for that is that they don't have a store near us," he said.
Aldi's pledge came as it reported a sales rise for last year, but saw profits fall sharply.
Last year, the company attracted more than 800,000 new customers, adding an extra £1.1bn in sales, up 11% on the previous twelve months. But most of this sales growth is from opening new stores.
Profits for the same period fell 18%, partly due to price cuts aimed at keeping its competitive edge.
Whilst the big established grocers are opening few, if any new stores, Aldi is still expanding, stealing their customers and growing market share. And that is set to continue.
"Over the next two years we're going to invest a further billion pounds in the UK and that shows our intent," says Mr Hurley, Aldi's chief executive for the UK and Ireland.
Aldi now has over 840 stores and is increasing its focus on London. It wants to double the number of stores inside the M25, from 45 to 100, by the end of 2025.
"Within Greater London, our market share is around half of what it is in the rest of the country so there's clearly a big opportunity for us to expand the business. In the long term, we can comfortably see us opening 200-250 stores within London," says Mr Hurley.
But will they be able to find enough locations to fit their low-cost business model?
"It's not straightforward as you don't have the parking spaces," says Adam Leyland, editor of the Grocer magazine.
"It's also harder to get good sites in London. So you have to have a very flexible model and Aldi is so formulaic as a discounter that this is harder to manage.
"But they are determined to do it and they are a very capable grocer. We've seen over the years how they've responded to the dynamics of the UK market."