March 18 (Reuters) - U.S. clothing retailer Gap Inc and luxury department store operator Neiman Marcus will close their stores for two weeks, joining other retailers in a vast effort to stem the spread of the novel coronavirus.

Gap will temporarily shut all Old Navy, Athleta, Banana Republic, Gap, Janie and Jack and Intermix stores across North America, starting March 19, the company said in a statement on Wednesday.

In a separate release, Neiman Marcus said it would shut all Neiman Marcus, Bergdorf Goodman, and Last Call stores in the United States, effective immediately.

Both retailers said they will keep their websites operating for shoppers and provide pay and benefits to store associates affected by the closures during the two-week period.

Several brick-and-mortar retailers have been struggling with disruptions to their businesses as cases of the highly-contagious respiratory illness rise in the United States.

It is widely expected that retail sales will suffer across the country as shoppers stay home to avoid catching the virus that causes the COVID-19 illness.

Numerous retailers including Tiffany & Co, Macy's Inc, L Brands Inc, Ralph Lauren and American Eagle Outfitters announced temporary store closures on Tuesday, joining Nike Inc and Nordstrom Inc, which made similar announcements in recent days.

The United States has seen a sharp increase in virus cases, with more than 6,469 infected and at least 109 deaths, as of Wednesday. (Reporting by Subrat Patnaik in Bengaluru; Editing by Bernard Orr)