Sgt La David Johnson was killed in an ambush in Niger
US President Donald Trump has denied controversial comments he is reported to have said about a soldier killed in action.
He is said to have told the wife of Sergeant La David Johnson, a Special Forces soldier, that "he knew what he signed up for".
Sgt Johnson among four US soldiers who were killed in an ambush in Niger.
The US president phoned Sgt Johnson's pregnant widow, Myeshia Johnson, and spoke to her for about five minutes according to ABC affiliate WPLG Local 10 in Miami.
The conversation happened shortly before Mrs Johnson and the couple's two children - a two-year-old son and six-year-old daughter - arrived at the airport to meet her husband's coffin.
With her was Frederica Wilson, a Democrat congresswoman for Florida.
Ms Wilson told WPLG that Mr Trump had said: "(Sgt Johnson) knew what he signed up for...but when it happens it hurts anyway."
She later tweeted: "Sgt La David Johnson is a hero. (Donald Trump) does not possess the character, empathy or grace to be president of the United States."
Sgt. La David Johnson is a hero. @realDonaldTrump does not possess the character, empathy or grace to be president of the United States.— Rep Frederica Wilson (@RepWilson) October 18, 2017
But Mr Trump has since tweeted, claiming: "Democrat Congresswoman totally fabricated what I said to the wife of a soldier who died in action (and I have proof). Sad!"
Democrat Congresswoman totally fabricated what I said to the wife of a soldier who died in action (and I have proof). Sad!— Donald J. Trump (@realDonaldTrump) October 18, 2017
A former Walmart employee, Sgt Johnson enlisted in January 2014 and became a decorated member of the prestigious 3rd Special Forces Group at Fort Bragg, North Carolina.
But the 25-year-old was killed on October 4th after his group was ambushed by more than 50 Islamist militants.
He was initially left behind during the evacuation and his body was retrieved nearly two days later.
Mr Trump was playing golf as Sgt Johnson's body arrived at Dover Air Force Base in Delaware on October 7th.
Mr Trump's phone conversation with Mrs Johnson comes just days after he was criticised for saying previous presidents had not called families of fallen services personnel.
He told NBC: "President Obama I think probably did sometimes, and maybe sometimes he didn't. I don't know, that's what I was told.
"All I can do, all I can do is ask my generals.
"Other presidents did not call. They'd write letters. And some presidents didn't do anything.
"But I like the combination of, I like, when I can, the combination of a call and also a letter."
The comments drew sharp rebukes, with some of Mr Obama's former White House aides expressing outrage at the claim.
Some critics say Mr Trump made them to distract attention from what happened to the four soldiers in Niger, which has not yet been fully explained.
The White House said Mr Trump had called all four families of those killed and "offered condolences on behalf of a grateful nation and assured them their families' extraordinary sacrifice to the country will never be forgotten".