KROGERS AND WALSH, Ohio — Kroger and Walmart will merge in the United States as the nation’s largest grocer and supermarket operator.

The U.S. Department of Justice said Monday that a federal court approved the transaction.

Kroger, the nation\’s largest grocery retailer, and Walmart, the largest discount retailer, announced last week that they would merge.

The transaction is subject to a preliminary review and final approval by a federal bankruptcy court.