(CNN) President Donald Trump on Thursday once again refuted a congresswoman's account of his call with the grieving wife of a slain US service member, deeming it a "total lie" hours after his own chief of staff seemed to bolster a key piece of her story.

"The Fake News is going crazy with wacky Congresswoman Wilson(D), who was SECRETLY on a very personal call, and gave a total lie on content!" Trump tweeted Thursday evening.

The Fake News is going crazy with wacky Congresswoman Wilson(D), who was SECRETLY on a very personal call, and gave a total lie on content!

Earlier this week, Rep. Frederica Wilson, D-Florida, said she overheard the President tell the grieving widow of a soldier who was killed in action in Niger that "he knew what he signed up for, but I guess it still hurt."

Thursday night's tweet comes the same day his chief of staff John Kelly took to the White House press briefing room lectern to defend Trump.

The chief of staff said he was "stunned" that Wilson had listened to the call on speaker phone, but he added that the message the President tried to convey included the idea that "he knew what he was getting himself into."

"In his way," Kelly said of Trump, he "tried to express that opinion. That he's a brave man, a fallen hero. He knew what he was getting himself into, because he enlisted. There's no reason to enlist, he enlisted. ... That was the message. That was the message that was transmitted."

Earlier Thursday, Joyce Jones, a spokeswoman for Wilson, said the congresswoman stands by her story, but "has decided to not make any further comment on this issue."

"The focus needs to be on helping a grieving widow and family heal, and should not be on her or Donald Trump," Jones said of Wilson. "She has nothing else to add but stands by the statement issued last night."