WASHINGTON, May 9 (Xinhua) -- The United States has undercounted the number of deaths caused by COVID-19, Anthony Fauci, top U.S. infectious disease expert, said on Sunday.

"You know, the model says that it's a significant amount, as you mentioned correctly, 900,000. That's a bit more than I would have thought the undercounting was, but, you know, sometimes the models are right on line, sometimes they're a bit off," Fauci said in a TV programme, responding to a question as to whether he believes the true death toll is as high as suggested by a new study from the University of Washington.

"But I think there's no doubt that we are and have been undercounting. What that tells us is something that we've known. You know, we're living through a historic pandemic, the likes of which we haven't seen in over a hundred years," he said.

The United States reported a total of 32,707,359 cases with 581,752 deaths as of Sunday, according to the Center for Systems Science and Engineering at Johns Hopkins University.