Washington (CNN) President Donald Trump was "very surprised" that his phone call with the widow of a US serviceman could have been taken badly, according to an interview with Fox Business Network's Maria Bartiromo.

Rep. Frederica Wilson, D-Florida, criticized the President this week over his handling of his call with the wife of Sgt. La David Johnson -- one of four soldiers killed in action in Niger earlier this month. Wilson, who heard the call, told CNN's New Day earlier this week that Trump did not know Johnson's name when he made the condolence call.

But in his interview with Bartiromo, the text of which was released by Fox Business, Trump seemingly contested the congresswoman's claim.

"And by the way, I spoke of the name of the young man and I -- it was a really -- it's a very tough call," Trump told Bartiromo. "Those are the toughest calls."

Wilson said she overheard the President tell the grieving widow that "he knew what he signed up for, but I guess it still hurt."

Read More