'Angry' Obama announces IRS leader's ouster after conservatives targeted.
Washington (CNN) -- President Barack Obama vowed Wednesday to hold accountable those at the Internal Revenue Service involved in the targeting of conservative groups applying for federal tax-exempt status, beginning with the resignation of the agency's acting commissioner who was aware of the practice.
In a brief statement delivered to reporters in the East Room of the White House, the president announced that Treasury Secretary Jack Lew had requested -- and accepted -- the resignation of acting IRS Commissioner Steven T. Miller.
The president said the "misconduct" detailed in the IRS Inspector General's report released Tuesday over the singling out of conservative groups is "inexcusable."
"Americans have a right to be angry about it, and I'm angry about it," Obama said.
"It should not matter what political stripe you're from. The fact of the matter is, the IRS has to operate with absolute integrity."
Miller was made aware of the agency's targeting of conservative groups in May 2012, according to the IRS, while serving as deputy IRS commissioner. He did not tell Congress about it when he testified before an oversight committee in July despite being questioned on the issue. Miller was named acting IRS commissioner in November.
Obama pledged to work "hand in hand" with Congress as it investigates, and he vowed new safeguards will be put in place at the IRS so that "this doesn't happen again."
In an internal message to IRS employees obtained by CNN, Miller said he would be stepping down as commissioner in early June.
"This has been an incredibly difficult time for the IRS given the events of the past few days, and there is a strong and immediate need to restore public trust in the nation's tax agency," Miller wrote.
"I believe the Service will benefit from having a new Acting Commissioner in place during this challenging period."
Watch video HERE