LAGUNA BEACH, Calif.— Amazon.com Inc. might need to spend billions of dollars in the future to prevent the sale of counterfeit goods, expired food or dangerous products on its platforms to preserve the customer trust that is critical to the company’s future, Amazon consumer chief Jeff Wilke said Tuesday.

The e-commerce giant has been buffeted by a wave of reports in recent months about its sale of unsafe or expired goods, including an article in The Wall Street Journal detailing the availability of more than 4,000 items that had been declared unsafe by federal agencies.

Speaking here at the WSJ Tech Live conference, Mr. Wilke said Amazon’s business depends on customers trusting the company. The company recognizes it could lose its status as a trusted brand if the perception builds that it isn’t policing the products it sells, he said. That is why last year it spent $400 million on technology and a staff of 5,000 people tasked with tracking counterfeit and unsafe items.

“We have to be vigilant and willing to spend hundreds of millions and eventually billions of dollars to protect our customers,” said Mr. Wilke, Amazon’s chief executive of world-wide consumer. He said the company is lobbying for stiffer federal penalties for counterfeiters.

In addition to customer concerns, Amazon faces pressure from antitrust regulators concerned about the company’s dual role as a seller of products and marketplace operator. The European Union, which announced an investigation of the company this summer, is probing whether Amazon is gaining a competitive advantage through the data it gathers from every transaction on its platform. In the U.S., the Federal Trade Commission is probing possible monopoly practices by Amazon.