The Department of Homeland Security is finalizing its plan for a biometric data system to track when immigrants leave the United States and will present it to Congress within "weeks," says a USA Today report.

John Cohen, the department's deputy counter terrorism coordinator, did not discuss the cost in his testimony about the problem of immigrants who overstay visas. He said the department's report to Congress will explain how DHS plans to better determine who has overstayed their visa.

Cohen said improvements in how data from immigrants is collected and stored has made it easier for law enforcement to identify visa overstays and determine if they pose a threat to national security or public safety.

Visa overstays have long been a concern of lawmakers and law enforcement. Some estimates suggest that as many as half of the country's estimated 11 million illegal immigrants have overstayed visas, says the report.