A spike in infections in Florida along with Texas, Arizona and California this month has overwhelmed hospitals and forced a U-turn on steps to reopen economies after the end of lockdowns put in place in March and April to slow the spread of the virus.
Florida, the third-most populous US state and a prized destination for beach-goers and retirees, had 191 coronavirus deaths in the prior 24 hours, its highest single-day rise since the start of the epidemic, the state health department said.
Texas, the second-most populous state, added more than 6,000 new cases on Monday, pushing its total to 401,477, according to a Reuters tally. Only three other states - California, Florida and New York - have more than 400,000 total cases.
Georgia, which borders Florida, reported 54 more deaths on Tuesday as its total number of cases rose to more than 175,000, according to its state health department.
The pandemic, which first surfaced in China late last year, has pushed the US death toll from COVID-19, the respiratory illness caused by the novel coronavirus, closer to the 150,000 mark just over three months before a Nov. 3 election in which President Donald Trump is seeking a second term in the White House.
The surge in cases in Florida prompted Trump last week to cancel his Republican Party's nominating convention events in Jacksonville in late August, and Major League Baseball has postponed some games in its truncated delayed season after a number of Miami Marlins members tested positive for the virus.
There is, however, a glimmer of hope in the data from Texas, where the state health department reported that current hospitalisations due to COVID-19 fell on Monday.
Dr. Anthony Fauci, a top US infectious diseases expert, said there were signs the recent surge could be peaking in hard-hit states like Florida and Texas while other parts of the country may be on the cusp of growing outbreaks.
"They may be cresting and coming back down," Fauci, head of the US National Institute of Allergy and Infectious Diseases, told ABC's "Good Morning America" program regarding the state of the outbreak in several Sunbelt states.
Fauci said there was a "very early indication" that the percentage of coronavirus tests that were positive was starting to rise in other states, such as Ohio, Indiana, Tennessee and Kentucky.
Fauci has become a lightning rod for some Trump supporters who accuse the 79-year-old health official of exaggerating the extent and severity of the US outbreak and playing down possible treatments.
Battle in Congress
The rise in US deaths and infections has dampened early hopes that the country was past the worst of an economic crisis that has decimated businesses and put millions of Americans out of work.
It also has fuelled a bitter debate over the reopening of US schools in the coming weeks. Trump and other administration officials have pushed for students to return to classrooms while some parents and teachers have voiced safety concerns.
Randi Weingarten, the president of the American Federation of Teachers, said, "Nothing is off table" and local "safety strikes" are possible if the health of educators and students is not protected.
"We will fight on all fronts for the safety of students and their educators," she said during the union's virtual convention on Tuesday. "It's the eleventh hour; we need the resources now."
In Washington, the US Congress was locked in difficult talks over another coronavirus aid package to help American families and businesses recover from the crisis.
Congress has passed about $3 trillion in aid including enhanced unemployment benefits to blunt the pain of lockdowns.
Senate Republicans pushed back against their own party's $1 trillion coronavirus package, which was hammered out with the White House and touted by Senate Majority Leader Mitch McConnell as a "tailored and targeted" plan.
"I'm not for borrowing another trillion dollars," Republican Senator Rand Paul told reporters.
Democrats also have rejected the proposal as too limited compared with their $3 trillion proposal that passed the House of Representatives in May. Some Republicans called that one too expensive.
The Republican proposal would give many Americans direct payments of $1,200 each, provide billions in loans to small businesses and help schools reopen. But it would slash the current expanded unemployment benefit from $600 per week in addition to state unemployment to $200 per week. The enhanced unemployment benefit expires on Friday.
