"We hope that he will have a wonderful career," Trump added.
Trump said "it was very sad when we heard about it."
Trump focused on Porter's denial of the allegations that he struck his two-ex-wives while they were married.
"He says he's innocent, and I think you have to remember that," Trump said. "He said very strongly yesterday that he's innocent, but you'll have to talk to him about that."
John Kelly facing questions
Trump's comments come as chief of staff John Kelly and other top White House officials are facing questions about why they did not act to remove Porter from his position after they found out about the allegations of domestic abuse.
Senior aides knew for months about the allegations levied against Porter by his ex-wives, even as Porter's stock in the West Wing continued to rise, multiple sources have told CNN. Porter denied the allegations but resigned on Wednesday.
Even after the allegations surfaced publicly, sources told CNN that Kelly did not urge Porter to resign or seek to force him out. Instead, the White House released a statement from Kelly praising Porter's character.
It wasn't until the uproar over the allegations grew and more details surfaced that Porter resigned and Kelly put out a second statement expressing concern about the allegations.
White House deputy press secretary Raj Shah acknowledged on Thursday the White House "could have done better" in its initial response to the allegations, a concession Trump was privately miffed about, CNN has learned.
The allegations against Porter and the problematic internal response to the allegations -- which former senior staffers had known about for months -- has led to tensions inside the West Wing, with Kelly's credibility in particular coming under fire.
Trump has also grown upset with his White House communications director Hope Hicks, who despite being in a romantic relationship with Porter helped craft the White House's initial pushback to the allegations, a source familiar said.
(©2018 Cable News Network, Inc., a Time Warner Company. All rights reserved. By Jeremy Diamond)
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