The head of the US Internal Revenue Service should resign due to the agency's inability to improve its defenses against hacks on taxpayer data, according to a Republican lawmaker.
Republican representative Barbara Comstock said new leadership was needed to replace IRS commissioner John Koskinen due to failures to secure Americans' sensitive information from malicious intrusions.
"Commissioner Koskinen has provided little confidence that cyber security is a top priority at the IRS," Comstock said in a statement, adding she was concerned the agency apparently has no one in charge of cyber security.
The IRS did not immediately comment.
More than 700,000 individuals may have had their personal information pilfered by hackers during an intrusion last year, the IRS revealed in February. That number has been repeatedly revised upward from initial estimates that were far smaller.
Comstock referenced a US Government Accountability Office report released last month that found the IRS struggling to upgrade its information security plan. The IRS agreed to work toward implementing dozens of outlined recommendations.
Koskinen appeared before congressional committees last week and said complying with the GAO recommendations was a priority.
The commissioner has been under near-constant fire from Republicans since he took over the agency in 2013 amid controversy over whether the IRS was targeting conservative groups.
More than 60 Republicans have signed on to a resolution introduced in October to impeach Koskinen on charges that he has impeded a congressional investigation into the IRS's treatment of conservative groups.
Comstock is the first lawmaker to call for Koskinen's resignation solely for cyber security reasons, an aide said.
Koskinen is not the first Obama administration official to be targeted by Congress for his handling of cyber security.
Last year Katherine Archuleta, head of the Office of Personnel Management, resigned after several lawmakers from both parties called for her ouster following the theft of personal data of more than 21 million individuals.
Comstock said Koskinen should follow the lead of Archuleta and other top executives who have left due to poor handling of hacks "to allow for new and trusted leadership at the IRS."