German discount supermarket group Lidl said it would open its first stores in the US ahead of schedule this summer and had planned 100 stores within a year.
The group also planned to open its first 20 stores in Virginia, North Carolina and South Carolina, it added in the statement.
Lidl with 10,000 stores in 27 countries in Europe, had not been expected to enter the US until late 2017 or 2018.
But US retailers had launched action to counter competition from the new player, with Kroger, the second-biggest US grocer after Wal-Mart expanding its own discount format, Ruler Foods. Also organic grocer Whole Foods last year launched a lower-price store concept named "365".
"Retailers are preparing themselves for Lidl's market entry. They are not falling asleep. They really take it seriously," said Milos Ryba from retail analysis firm IGD, speaking before the timing of the Lidl openings were announced, Reuters reported.
The US already had German discounter Aldi running 1,600 stores, but Lidl was seen as a bigger threat as in recent years recent it had shifted focus from discounts and was working of new strategies such as ecommerce.
Meanwhile, Lidl had a facility, in Fredericksburg, Virginia, a prototype store, which it was using the space to test which details appealed to US shoppers.
The prototype store was significantly larger than what was typical for Lidl overseas.
According to US chief executive Brendan Proctor the store, with 21,000 square feet of shopping space, was 35 per cent larger than some of the chain's biggest stores in Europe. The company had decided on the larger format as it thought that it would need to offer a wider array of merchandise to compete in the US market.