WASHINGTON — President Trump found himself embroiled in yet another emotional argument Wednesday over a commander-in-chief's most sensitive duty: Calling families of the fallen.

All day, Trump engaged in a battle of words with Rep. Frederica Wilson, D-Fla., about whether he was disrespectful to the widow of a soldier killed in the west African nation of Niger. By the afternoon, he was embroiled in another controversy — whether he promised the father of another soldier killed in combat a $25,000 check from his personal account.

Trump said Wilson was lying when she said he told the widow of slain Sgt. La David Johnson that "well, I guess he knew what he signed up for, but I guess it still hurt."

Trump challenged Wilson to make the accusation again, which she promptly did.

"Democrat Congresswoman totally fabricated what I said to the wife of a soldier who died in action (and I have proof). Sad!" Trump tweeted early Wednesday, the morning after Wilson recounted the conversation in an interview on CNN.

Trump never produced any "proof" and aides said there was no recording of the conversation that took place Monday night, while Wilson repeated her claim in a string of television interviews Wednesday.

"I didn't hear the whole phone call but I did hear him say, 'I'm sure he knew what he was signing up for but it still hurts," Wilson said in a follow-up interview on CNN, describing the president's comments as offensive.

Wilson also called Trump "a sick man. He's cold-hearted and he feels no pity or sympathy for anyone."

Delayed reaction

The dispute surfaced when Trump took heat for not commenting on the Oct. 4 attack that killed four U.S. soldiers in Niger, and then making the false claim that previous presidents had not called families of troops killed in action.

At the White House, a visibly angry Trump told reporters that "I didn't say what that congresswoman said, didn't say it at all, she knows it." The president said, "I had a very nice conversation with the woman, with the wife, who sounded like a lovely woman."

Asked about his "proof" contradicting Wilson's claim, Trump said: “Let her make her statement again and then you’ll find out.”

More:Soldier's mom backs claim Trump said fallen soldier 'knew what he signed up for'

Related:With Trump, even a call to an Army widow becomes a politicized fight

Trump spoke by phone Tuesday with Myeshia Johnson, Johnson's widow. Johnson was killed on Oct. 4, but Pentagon records show his body was not recovered until Oct. 6.

White House spokeswoman Sarah Sanders said Trump did not have a recording of the call, but "there were several people in the room" for a conversation she described as "completely respectful."

Sanders did not dispute that Trump may have used phrase "knew what he was signing up for" and referred to Johnson as "your guy" in his conversation with the widow. But she said Trump was totally sympathetic to the widow, and is "appalling" that WIlson "has politicized this issue, and the way she is trying to make this about something that it isn’t."

Ambushed in Niger

Johnson's mother, Cowanda Jones-Johnson, seconded Wilson's statement about the phone call, telling The Washington Post: “President Trump did disrespect my son and my daughter and also me and my husband."

The attack in Niger that killed Johnson and three others has been a sore spot with the administration for two weeks.

On Oct. 4, four members of U.S. Special Forces on a counter-terrorism mission died after an ambush near the Niger-Mali border, the deadliest combat incident since Trump took office in January.

Trump did not comment publicly on the incident until a reporter asked him Monday why he had not contacted the families.

"I've written them personal letters," Trump said. "They've been sent, or they're going out tonight, but they were written during the weekend. I will, at some point during the period of time, call the parents and the families, because I have done that traditionally."

He added: "If you look at President Obama and other presidents, most of them didn't make calls."

Aides to Obama and ex-President George W. Bush said they had frequent calls and visits with families of the fallen.

"This is an outrageous and disrespectful lie even by Trump standards," tweeted Ben Rhodes, former national security aide to Obama.

Sanders said that White House chief of staff John Kelly heard Trump's call to Johnson, but Kelly has not commented publicly on that. On Tuesday, the White House claimed that Obama did not call Kelly, a retired Marine general, when his son, Robert, was killed in Afghanistan in 2010.

On Tuesday night, the White House announced that Trump had phoned the families of the four soldiers killed in Mali.

Sanders said the president "offered condolences on behalf of a grateful nation and assured them their family's extraordinary sacrifice to the country will never be forgotten."

Why the wait? Sanders said there is a process undertaken by the Pentagon and the White House to ascertain details about the slain soldiers. Trump received final reports Monday on soldiers killed in Niger.

A peculiar promise

On Wednesday afternoon, the Post reported that Trump spoke to the father of Army Cpl. Dillon Baldridge, who was killed in Afghanistan on June 10. When the father, Chris Baldridge, expressed frustration that the $100,000 military benefit would go to his ex-wife, Cpl. Baldridge's mother, Trump said, ‘I’m going to write you a check out of my personal account for $25,000,’ the Post reported.

The Post story said that while Trump made the promise during the summer, Chris Baldridge had not received the check.

When Trump sent a condolence letter, “I opened it up and read it, and I was hoping to see a check in there, to be honest,” the Post reported that Chris Baldridge said. “I know it was kind of far-fetched thinking. But I was like, ‘Damn, no check.’ Just a letter saying ‘I’m sorry.’"

Late Wednesday afternoon, White House spokeswoman Lindsay Walters told the Post that Trump had sent the check.