A host of U.S. states have seen sharp climb of COVID-19 cases in recent days, raising fears of a new wave.

On Tuesday, nine states -- Alabama, Arizona, Florida, Nevada, North Carolina, Oklahoma, Oregon, South Carolina and Texas -- either reported new single-day highs or set a record for seven-day new case averages, according to an analysis by The Washington Post.

That trend continued in some states Wednesday. Oklahoma registered another record for single-day new cases, and California set another record in its rolling average, while North Carolina's average dropped by one case, breaking a streak of 15 new highs in a row.

The confirmed COVID-19 cases in the United States have surpassed 2,157,000 as of Wednesday evening, with over 117,000 deaths, according to Johns Hopkins University tally.

An influential COVID-19 model produced by the Institute for Health Metrics and Evaluation (IHME) at the University of Washington has revised its projections, forecasting nearly 170,000 COVID-19 deaths in the United States by Oct. 1.

As all 50 states moved to relax restrictions, hot spots have emerged in states such as South Carolina and Missouri and cities such as Houston and Phoenix. Week-over-week case counts are on the rise in half of all states, according to a report by The Hill.

Meanwhile, infections have dwindled in other states that were initially hit harder.

The reopening of businesses nationwide and planned school resumption are drawing growing concerns for a new wave of infections.

"There are blueprints that will allow businesses and schools to open safely. If they follow these blueprints it will be possible to operate safely," Robert Schooley, a professor of medicine with the Division of Infectious Diseases and Global Public Health at the University of California, San Diego, told Xinhua.

He said in some places in the country, it is likely that businesses will do very well. But in others, where public health measures are not taken seriously, the population will be at a "significantly increased risk" for a resurgence of the disease.

"The priorities need to be helping the public understand that the virus is real, the outbreak is real, the deaths are real... and that we do know what works to control SARS-CoV-2," Schooley told Xinhua.

He cited New Zealand as an example, saying it has virtually eliminated the virus from the entire country using science-based public policies that were consistently articulated by convincing political leaders and assiduously followed by the vast majority of the population.

"At the end of the day if the public does not see the threat real, the countermeasures we know from experience that work will not be adopted by enough of the public to end the epidemic," he said.

According to Stanley Perlman, a professor of microbiology and immunology at the University of Iowa, the United States might not see a "turning point" for a year.