The deal, which was announced in mid-October, has drawn fire from lawmakers and consumer groups amid concerns the tie-up of the No. 1 and 2 standalone grocers in the United States could boost already-high food prices and stifle competition.
The chief executives of both companies defended the merger to the U.S. Senate committee late in November, with Kroger's top boss Rodney McMullen saying that the combined company would still be much smaller than Walmart Inc.
The request from FTC extends the required waiting period until 30 days after the companies have "substantially complied" with the requests, Kroger said.
The company added it still expects to complete the deal in early 2024.
(Reporting by Deborah Sophia in Bengaluru; Editing by Saumyadeb Chakrabarty)