• As the spread of the coronavirus in the U.S. slows and the vaccine rollout out quickens, states have started loosening restrictions.
• Republican governors in Montana and Iowa lifted statewide mask-wearing requirements this month. North Dakota's mask mandate expired in January.

Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said Sunday it's too early for states to lift mask-wearing mandates given the high number of daily coronavirus cases and deaths in the U.S.

"We still have 100,000 cases a day. We still have somewhere between 1,500 and 3,500 deaths per day," Walensky said during an interview on CBS's "Face the Nation." "And yet we see some communities relaxing some of their mitigation strategies. We are nowhere out of the woods."

As the spread of the virus in the U.S. slows and the vaccine rollout out quickens, states have started loosening restrictions. Republican governors in Montana and Iowa lifted statewide mask-wearing requirements this month. North Dakota's mask mandate expired in January.

Back in September, Mississippi lifted its statewide mask mandate and later replaced it with a mandate covering 75 of the state's 82 counties. That more limited order has been extended through March 3.

In New York, Democratic Gov. Andrew Cuomo recently permitted indoor dining at 25% capacity despite the high risk of contagion in indoor spaces and opened up stadiums and arenas at limited capacity.

The U.S. is reporting more than 93,000 cases a day on average, down 22% from a week ago, and more than 3,000 deaths daily, up 4% from a week ago, according to a CNBC analysis of data from Johns Hopkins University.

The daily average of Covid deaths may have increased over the past week due to some states conducting audits and locating previously unreported fatalities.

More than 480,000 people in the U.S. have died from the virus and more than 27 million have been infected.

Health experts fear that the rapid spread of more contagious variants could bring a new surge in cases and deaths in the U.S. Cases of the more contagious variant first found in Britain, known as B.1.1.7, are doubling about every 10 days across the country.

"If we relax these mitigation strategies with increasing transmissible variants out there, we could be in a much more difficult spot," Walensky said. "Now is the time to not let up our guard. Now is the time to double down."

Health officials are urging Americans to tighten and double up on masks, which provide significant protection against the viral transmission. Recent research from the CDC suggests that tightly worn surgical masks or doubling up with a surgical and cloth mask reduces risk of transmission by up to 96%.

"We need to get our communities back to some normal functioning before we can start thinking about letting up our mitigation strategies," Walensky said.