(CNN)Dr. Deborah Birx on Sunday said the US is in a new phase in its fight against the coronavirus pandemic, saying that the deadly virus is more widespread than when it first took hold in the US earlier this year.
"What we are seeing today is different from March and April. It is extraordinarily widespread. It's into the rural as equal urban areas," Birx, the White House coronavirus task force coordinator, told CNN's Dana Bash on "State of the Union."
Birx stressed that Americans need to follow health recommendations, including wearing a mask and practicing social distancing.
"To everybody who lives in a rural area, you are not immune or protected from this virus," Birx said. "If you're in multi-generational households, and there's an outbreak in your rural area or in your city, you need to really consider wearing a mask at home, assuming that you're positive, if you have individuals in your households with comorbidities."
"This epidemic right now is different and it's more widespread and it's both rural and urban," she added.
A new ensemble forecast, published by the US Centers for Disease Control and Prevention, projects more than 173,000 American deaths by August 22, and former US Food and Drug Administrator Dr. Scott Gottlieb warned on CNBC last month that the coronavirus death toll could double to 300,000 deaths by the end of the year, if the country doesn't change its trajectory.
On Sunday, Birx would not give a projection of how many deaths the US would see by the end of year, but she said a death toll largely depends on southern and western states to maintain and accelerate their mitigation efforts. Those states have become hot spots for the virus.
"It's not super spreading individuals, it's super spreading events and we need to stop those. We definitely need to take more precautions," Birx told Bash.
Birx said each state needs a "dramatically tailored" approach to Covid-19, with a "set of recommendations based on what we are seeing at the community level, what we are seeing relevant to the hospitals."
The Trump administration has left many of the response decisions to state leaders, allowing governors to decide when to enforce or roll back coronavirus restrictions and when to close and reopen their state's economy. A key question has been whether state and local leaders should allow in-person schooling as many near the start of the school year.
Bash on Sunday asked Birx if schools in states with a 5% positivity rate should remained closed or have distance learning only.
"If you have high case load and active community spread, just like we are asking people not to go to bars, not to have household parties, not to create large spreading events, we are asking people to distance learn at this moment so we can get this epidemic under control," Birx responded, though she deferred to CDC guidelines on school reopenings.
Birx's comments come as the US has reported more coronavirus cases and deaths than any other country.
As of Sunday, the US had reported more than 4.6 million cases of Covid-19 and at least 154,449 Americans have died, according to data from the Johns Hopkins University.
This story has been updated with additional comments from Dr. Deborah Birx on "State of the Union."