Covid-19 cases continue to surge in some parts of the country and the public health officials are trying to work with governors to tailor responses for each state.
"We are in a new phase," said Dr Deborah Birx. "What we are seeing today is different from March and April. It is extraordinarily widespread" in rural as well as urban areas.
"To everybody who lives in a rural area: You are not immune or protected from this virus," Birx said on CNN's State of the Union on Sunday.
Birx, the White House task force coordinator, said people living in multigenerational households in an area that is experiencing an outbreak should wear masks inside the home to protect the elderly or those with underlying conditions.
Admiral Brett Giroir, an assistant Health and Human Services secretary, continued to stress the importance of wearing masks.
"If we don't do that, and if we don't limit the indoor crowded spaces, the virus will continue to run," he said on NBC's Meet the Press.
"We are very concerned and this is a very serious point."
The coronavirus, which first appeared in China, has infected 4.6 million people in the US and killed more than 155,000 Americans, according to a Reuters tally.
Birx said federal officials have been working on individual reports for each state examining community trends and hospital records. "Each of these responses have to be dramatically tailored," she said.
She said what she witnessed as she visited 14 states over the last three weeks gave her cause for concern.
"As I travelled around the country, I saw all of America moving," Birx said. "If you have chosen to go on vacation into a hot spot, you really need to come back and protect those with comorbidities and assume you're infected."
If people wear masks and avoid crowds, Giroir said, it gives the same outcome as a complete shutdown.
"That's why we're going to all the states, we're on local radio, we give specific instructions to every governor by county, what they need to do when we start - when those counties start tipping yellow, because that's the time when you have to stamp it down," he said.
