WASHINGTON, March 1 (Xinhua) -- Director of the U.S. Centers for Disease Control and Prevention (CDC) Rochelle Walensky warned Monday the country is at risk of losing its recent progress in the battle against COVID-19 if states are rolling back health measures.

"I am really worried about reports that more states are rolling back the exact public health measures we have recommended to protect people from COVID-19," she said.

"At this level of cases with variants spreading, we stand to completely lose the hard earned ground we have gained," she said.

After weeks of tumbling case numbers, new infections are on the rise again, about 2 percent more this past week compared to the previous week, according to Walensky.

Similarly, the most recent seven-day average of deaths has also increased more than 2 percent, to nearly 2,000 deaths per day.

She called on the public to continue wearing well-fitting masks and taking other public health prevention actions.

"It is so critical that we remain vigilant and consistently take all of the mitigation steps we know work to stop the spread of COVID-19 while we work our way toward mass vaccination," she said.

The United States has recorded over 28.6 million cases with more than 513,900 related deaths as of Monday afternoon, according to the real-time count kept by Johns Hopkins University.