Amazon is taking drastic steps to prioritize delivery of essential items while pausing shipments of non-essential products to its warehouses as it tries to manage its supply chain strained by coronavirus-related demand.

Amazon will still deliver products purchased by consumers for any category that is in stock. It has just asked sellers and retailers not to ship more nonessential items to its warehouses until at least April 5.

On Tuesday, Amazon sent an email to marketers and sellers outlining its new emergency response measures, reacting to shortages and delays on high-demand products, including groceries and cleaning supplies.

“We are seeing increased online shopping, and as a result some products such as household staples and medical supplies are out of stock,” Amazon wrote in its email to brands and sellers. “With this in mind, we are temporarily prioritizing household staples, medical supplies, and other high-demand products coming into our fulfillment centers so that we can more quickly receive, restock, and deliver these products to customers.

“For products other than these, we have temporarily disabled shipment creation,” the email said. “We are taking a similar approach with retail vendors.”

Ad Age received a copy of the email from a marketing executive on condition of anonymity.

Here is what is changing: Amazon told brands and sellers to temporarily pause shipments of nonessential products to its warehouses, so it can focus on handling high-priority goods, like food, medical supplies and household cleaning supplies. Amazon is accepting items that have already been shipped to its warehouses and will deliver those to consumers, as well as fulfill new orders on goods it already has in stock. However, Amazon is not taking on new inventory for nonessential products until at least April 5. Amazon has not given a detailed list of all the products it considers essential. Vendors and brands that don’t use Amazon to ship their products—those that rely on other distribution channels—are not expected to be affected by the new order.

“We understand this is a change for our selling partners and appreciate their understanding as we temporarily prioritize these products for customers,” an Amazon spokesman said in an email statement.

Amazon has faced shortages of goods like Clorox and Lysol disinfectant wipes. Also, food stocks have dwindled. This week, Amazon said it would hire an additional 100,000 people to keep its deliveries moving to consumers who are shut in during the coronavirus pandemic.

Coronavirus has been a global concern since January, when it first emerged in China. It has since led to a state of emergency in the U.S.

Retailers have come to rely on Amazon as their main distribution point to consumers as its platform takes a growing share of the e-commerce market. EMarketer estimates that Amazon accounts for close to 40 percent of all e-commerce in the U.S.

“Brands need to be very flexible during these uncertain times,” says Mark Power, CEO of Podean, an Amazon marketing services firm. “They may push into Amazon aggressively because that’s the way consumers are reacting now, gravitating toward these marketplaces to deliver items essential to their daily lives. But Amazon also needs to be realistic about what it can do now, responding to this huge demand coming from the world of consumers.”