(CNN) A Democratic senator who received the Purple Heart after losing both her legs in the Iraq War lambasted President Donald Trump for playing a "sick political game" with the deaths of fallen US service members.

During an interview on CNN's " Erin Burnett Outfront ," Sen. Tammy Duckworth of Illinois said she had "utter disgust" for the way Trump has politicized his interactions with Gold Star families.

Trump has been criticized this week over his handling of a phone call with Myeshia Johnson, the widow of Sgt. La David Johnson, one of four soldiers killed in Niger

But Trump claimed in a tweet that the remarks were "fabricated" by the congresswoman and also told reporters, "I didn't say what that congresswoman said, and she knows it."

On Monday, Trump had faced questions about why he waited nearly two weeks to publicly address the deaths.

Trump claimed that former President Barack Obama did not make calls to the families of slain service members, and in a radio interview the next day, said Obama did not call White House chief of staff John Kelly when his son, 1st Lt. Robert Michael Kelly, was killed while serving with the Marines in Afghanistan in 2010.

Kelly was "disgusted by the way that this has been politicized," according to the White House, but Duckworth argued that if anyone is to blame for that, it is the President.

"For him to have done this and played games with Gold Star families is absolutely unacceptable -- Gold Star families are sacred," Duckworth said Wednesday.

"The President is the one who politicized a Gold Star family, and he continues a trend that began from even before he was elected," she said. "There's only one person here who's attacked a Gold Star family, and that is this President, and for him to continue to use Gold Star families as pawns in whatever sick political game he's playing is not honoring the men and women who laid down their lives to defend this country."

Family members of fallen service members will also be reluctant to ask for help in the future, Duckworth warned, "because they have a President, a commander in chief, who's going to use their grief for his own political gain."

Duckworth said she has no doubts about whom to believe about what was said during the phone call.

"Let me tell you, if you ask me who I'm gonna believe, I'm gonna believe the family members who just lost their loved ones before I believe Donald Trump," she said.