The United States had "learned to live with," the flu season "just like we are learning to live with Covid, in most populations far less lethal!," Trump's post reads.
Doctors and scientists are working to estimate the mortality rate of COVID-19, but it is thought to be substantially higher -- possibly 10 times or more -- than that of most strains of the flu, according to Johns Hopkins University.
Trump's post is hidden behind a warning label on Twitter and users must click on "View" to see it.
"This Tweet violated the Twitter Rules about spreading misleading and potentially harmful information related to COVID-19," the Twitter warning label said. "However, Twitter has determined that it may be in the public's interest for the Tweet to remain accessible."
Facebook spokesperson Andy Stone told CNN that the social media company removed the post for similarly breaking its rules on spreading COVID-19 misinformation.
As of Tuesday morning, COVID-19 has infected over 7.4 million people in the United States and killed over 210,300, the Johns Hopkins University global tracker shows.
From the 2019-20 seasonal flu, an estimated 22,000 people died in the United States, according to the Centers for Disease Control and Prevention. The deadliest flu season since 2010 was in 2017-18, with an estimated 61,000 deaths, the CDC data shows.
His physician, Dr. Sean Conley, said Monday the president, "may not entirely be out of the woods yet." Once he got back to the balcony at the White House Trump removed his mask and saluted as he posed for photographs.
A new Cornell Alliance for Science study based on a thorough review of almost 40 million English-language news reports worldwide found that Trump "was likely the largest driver of COVID-19 misinformation during the COVID-19 pandemic," which researchers referred to as an "infodemic."
Twitter and Facebook also removed a post from Trump in August for similarly making false claims about the coronavirus.
In the August post, Trump falsely claimed that children are "almost immune" to the virus.
On Tuesday afternoon, Trump tweeted, "Repeal Section 230!"
Trump did not make clear exactly what he was referring to, but Section 230 is shorthand for part of U.S. law that allows tech companies immunity for nearly all of their decisions about content moderation.