WASHINGTON, July 5 (Xinhua) -- The United States opening up too early, mixed messaging on masks and social distancing have caused an alarming surge in the COVID-19 cases in the country, according to a U.S. health expert.

Dr. Ashish Jha, director of the Harvard Global Health Institute, said Sunday that the country opened up "a little too early in some places, a lot of states didn't meet the White House's own guidelines for when to open up safely."

"We didn't have the kind of testing and tracing infrastructure that we needed [and] last but not least there's been a lot of mixed messaging on masks and social distancing and so all of that has contributed to what I think is a perilous moment for our country," he told "Fox News Sunday."

He also noted that the decrease in the death toll from the virus is a "lagging indicator," which could also be explained by other factors, such as more cases among young patients who are more likely to survive.

Asked about U.S. President Donald Trump's event at Mount Rushmore for the Fourth of July weekend, the expert called on Trump to adhere to science, encourage people to wear masks and conduct social distancing.

"I'm perplexed why we're not doing the things we can do pretty easily to lower the risk," he added.