Secretary of Veterans Affairs Eric Shinseki said Thursday he's "mad as hell" over allegations that VA employees manipulated data to make wait times seem less than what they actually were.

Shinseki's appearance before a Senate committee comes on the heels of the deaths of 40 veterans in Phoenix who were waiting for health care at the VA.

Shinseki has faced calls to resign from veterans groups including the American Legion. However he said Thursday he will not resign until the mission is complete or until he is asked to resign by President Obama.