Other reporters who were close to Wahl told the AP news agency that he collapsed during the extension.
Wahl is said to have been taken to hospital but they were unable to revive him.
Ned Price, spokesperson for the US Foreign Ministry, regrets the death on Twitter.
"We are working with the Qatari authorities to ensure that his family's wishes are met as quickly as possible," he writes.
On Monday, Wahl, who was covering his eighth World Cup, wrote that he had sought treatment in Qatar.
“My body finally broke.
Three weeks of little sleep, high stress levels and a lot of work can do that,” Wahl wrote.
“What had been a cold for the past ten days turned into something more serious the night the USA played the Netherlands, and I had increased pressure and discomfort in my chest.
I didn't have covid (I get tested regularly here), but I went to the clinic at the media center today, and they said I probably have bronchitis.
They gave me a course of antibiotics and strong cough medicine, and I'm already feeling a little better just a few hours later.”
Arrested for wearing rainbow symbol
The news of his death came just weeks after he was arrested ahead of the USA's opening game against Wales when he was wearing a t-shirt with a rainbow symbol.
He was subsequently detained for half an hour before being released.
The American Football Association writes in a statement on Twitter that one could always turn to Grant Wahl for knowledgeable and entertaining analysis of the sport.
"Grant made football his life's work and we are devastated that he and his brilliant pen are no longer with us."
Grant Wahl was 48 years old.