The White House was not fully aware of the extent of the domestic abuse allegations against former White House aide Rob Porter until photographs emerged of an ex-wife with a black eye, a spokesman says.
The White House, which had backed Porter until the photo was published amid allegations of domestic abuse, said Porter's last day as staff secretary was on Wednesday, when he resigned.
Porter had not yet been approved for a security clearance because the required background check was still ongoing, White House spokesman Raj Shah said.
He said President Donald Trump was not aware of any issues with Porter's security clearance before Tuesday and "was surprised" by the abuse allegations.
"He, like many of us, did not see that in Rob Porter, did not see what these allegations have brought forward. So he was surprised by it. He was disheartened by it. He was saddened by it," Shah said at a news briefing.
He said chief of staff John Kelly was not "fully aware" of the extent of the allegations when he made his initial statement supporting Porter on Tuesday.
Kelly released a second statement on Wednesday saying he stood by his previous comments about Porter but was "shocked" by the allegations.
Kelly's handling of the situation was causing some in Washington to question his political judgment and management skills.
"Sometimes good people make bad decisions," Republican Senator John Kennedy told CNN.
"I don't care who you are, even if you are a Rhodes scholar, you can't beat the hell out of your spouse. It's wrong."
Senator Martin Heinrich, a Democrat, said if Kelly "covered up Staff Secretary Rob Porter's record of domestic violence then he should resign immediately".
There is no sign, however, that Kelly is in danger of losing his job. A staffer familiar with the president's thinking said Trump felt Kelly "does a good job" and Trump rose to Kelly's defence when it seemed the media was out to get him.