"We can't reveal the other four stores we will close before the end of lease terms at the moment as we still need to have commercial discussions with landlords," Mr Walker said.
"When we have more information we will be letting our customers and team know. But we are committed to serving the community of Whanganui," he said.
Mr Walker said over the next 12 months the group will open three new stores and two replacement stores.
He said this year Progressive Enterprises would be employing 600 more people bringing the total staff level to more than 18,000.
But First Union, which represents about 6500 supermarket workers, told Radio NZ they had no idea where the other four stores were.
Secretary Maxine Gay said they wanted Countdown to say where those supermarkets were because "it's had an incredibly unsettling effect on all Countdown workers".
"They're calling the union and their organisers, wanting to know whether or not it's their shop, how safe they are and we of course are not able to tell them, because we don't know," Ms Gay said.