A U.S. senator from New Jersey is urging the Federal Trade Commission to investigate how hackers accessed credit and debit card accounts at Target, putting 40 million customers at risk of identity theft.

Standing in front of a Target store in Jersey City, Democrat Bob Menendez says he doesn't know why the retail chain didn't have better systems in place to protect customers' personal information.

"If there was a better standard of security to achieve the goal of protecting their consumers, and they did not invest in making that standard, then that's a judgment I'm sure that will be litigated in court," he said."

Menendez said that, if the FTC lacks clear power to fine a company for failing to protect consumer data, he'll introduce legislation to give it that authority. He says that would be an inducement for companies to enhance their security to prevent what happened at Target.

:They have to put in the equation if I have a large fine and penalty, I might as well make the investment, not have the breach, not have the lack of confidence of my customers," he said. "That would be a far better decision, and hopefully if they're not making it on their own, we'll help them make that decision."

Menendez noted that he's also sponsored a bill to improve cybersecurity coordination among government, and to fund research into a national cybersecurity strategy.

The No. 3 U.S. retailer said last week that hackers stole data from as many as 40 million cards used at Target stores during the first three weeks of the holiday shopping season.  This was the second-largest data breach in U.S. retail history.

Target has not said how its systems were compromised, though it described the operation as "sophisticated." The U.S. Secret Service and the Justice Department are investigating, but declining comment.

This article includes information from the Associated Press.