"I think it's fair to say that we all could have done better over the last few days in dealing with this situation", Raj Shah, a deputy press secretary, said.
"The fact that Porter might have held a senior White House position without a security clearance is troubling and merits a full investigation", said Chris Lu, former Cabinet secretary under President Barack Obama and senior fellow at the University of Virginia Miller Center. "I didn't go the police because I was scared, I was in Italy alone and I didn't know what to do".
"We were relying on the information we had", Shah said.
President Donald Trump stood by Porter, even though he accepted the 40-year-old Rhodes Scholar's resignation. "I took the photos given to the media almost 15 years ago and the reality behind them is nowhere close to what is being described", Porter said in a statement. "Hicks played a significant role initially in drafting the statements defending Porter".
Porter's ex-wife, Jennifer Willoughby, told the DailyMail.com - the USA website of a United Kingdom tabloid - that he had difficulty controlling his anger and at one point pulled her out of the shower and yelled at her.
Porter's first wife, Colbie Holderness, told the Daily Mail that Porter choked and punched her during the five years they were married. Porter said he will leave the White House after a transition period.
Speaking with reporters in Japan, Pence - who's on his way to the Winter Olympics in South Korea - said he had just learned of the accusations against Porter that morning and wouldn't comment on them until he was back in the states.
Winter Storm Watch in metro Detroit issued for Thursday night, Friday
Although temperatures warm up a bit today to the 30's and 40's in central Montana, another winter storm is looming on the horizon. The bulk of the snow will come through Thursday night and early Friday, with snow tapering off during the day Friday.
Porter has denied the allegations brought forth by his ex-wife, calling them "outrageous" and "simply false".
Earlier in the day, Trump addressed the 66th Annual Prayer Breakfast, in Washington, telling the gathering of more than 3,800 elected officials and religious leaders on hand: "America is a nation of believers and together we are strengthened by the power of prayer". Trump vigorously defended Roy Moore, the failed Alabama Republican Senate candidate, against allegations that included child molestation, and Sanders has said that multiple women who have accused the president of sexual misconduct were lying.
Porter previously served as chief of staff for Sen.
Shah, who began his maiden briefing two-and-three-quarter hours later than scheduled, insisted that Trump still has confidence in Kelly and his communications director, Hope Hicks, who had recused herself from "some matters" regarding Porter.
"President Trump's framework would end the visa lottery program and reallocate some of the visas to help reduce backlog of high-skilled, employment-based immigrant cases", the White House said. He worked with chief of staff John Kelly on "trying to impose order" in a White House known for feuding staff and disorganization.
The White House was also put on the defensive about Porter's interim security clearance, fielding questions about how someone could handle some of the nation's most sensitive documents while potentially being ripe for blackmail.
Attorneys who specialize in security clearance said Porter should have disclosed the allegations, including the protective order granted to one woman, when he filed his lengthy national security application.