US Attorney General Eric Holder urged Congress on Monday to create rules that would require companies to quickly inform customers when their personal electronic data has been stolen.

Holder's call comes two months after Target, the second-largest US discount retailer, suffered a massive data breach that affected millions of customers.

While authorities are working to track down those responsible for the Target hack, "it's time for leaders in Washington to provide the tools we need to do even more: by requiring businesses to notify American consumers and law enforcement in the wake of significant data breaches," Holder said in a video statement.

He called on Congress to "create a strong, national standard for quickly alerting consumers whose information may be compromised."

This would allow law enforcement "to better investigate these crimes - and hold compromised entities accountable when they fail to keep sensitive information safe."

Target initially reported on December 19 that hackers had obtained the payment card data of some 40 million customers.

On January 10, however, it said its own investigation had revealed that hackers also stole a second batch of data that included names, mailing addresses, phone numbers or email addresses for up to 70 million people.

Security researchers have said that the breach is probably linked to a broader global network of cybercrime that may have affected other merchants.