The Internal Revenue Service is doing everything possible to ensure that individuals and groups dealing with the agency will be treated fairly regardless of their political views, IRS Commissioner John Koskinen said Tuesday.

Koskinen told a Senate committee that the IRS remains committed to fixing issues stemming from a 2013 report that the agency was unfairly targeting select Republican political organizations applying for 501(c)(3) and 501(c)(4) status. The targeting led to criminal probes by both the Department of Justice and the FBI.