Coronavirus USA: Pence defends Dr. Fauci despite criticism Latest headlines:

Tennessee doctors and teachers question reopening schools

As many school districts prepare for students to return to classrooms in the coming weeks, a group of Tennessee doctors, health care workers and even teachers are calling the return to school "insane and irresponsible."

Dr. Amy Gordon Bono, a primary care doctor practicing internal medicine in Middle Tennessee, spoke out on behalf of ProtectMyCare, a coalition of doctors who have been outspoken throughout the coronavirus pandemic.

A pandemic of the novel coronavirus has now killed more than 540,000 people worldwide.

Over 11.6 million people across the globe have been diagnosed with COVID-19, the disease caused by the new respiratory virus, according to data compiled by the Center for Systems Science and Engineering at Johns Hopkins University. The actual numbers are believed to be much higher due to testing shortages, many unreported cases and suspicions that some governments are hiding the scope of their nations' outbreaks.

Since the first cases were detected in China in December, the United States has become the worst-affected country, with more than 2.9 million diagnosed cases and at least 131,238 deaths.

Latest headlines:

US formally submits notice it will withdraw from WHO, official says

For 1st time since March, CT reports no COVID-19 deaths

At least 21 states have reversed, paused reopening

Brazil's President tests positive for COVID-19

Here is how the news is developing today. All times Eastern.

5:30 p.m.: US formally submits notice it will withdraw from WHO

The U.S. has notified the World Health Organization that it will formally withdraw from the body next year, a senior Trump administration official said.

"The United States' notice of withdrawal, effective July 6, 2021, has been submitted to the U.N. Secretary-General, who is the depository for the WHO," the official said in a statement Tuesday.

The United Nations confirmed Tuesday it had received the letter and is verifying with the WHO that the U.S. meets the conditions for withdrawal, which include giving a year's notice and payment of all financial obligations.

When contacted by ABC News, a WHO spokesperson did not have any further details at this time.

President Donald Trump had said in late May the U.S. would end its partnership with the WHO and be "redirecting those funds to worldwide, and deserving, urgent global public health needs."

Trump's move to pull out of the WHO during a pandemic have been met with criticism. Bob Menendez, the top Democrat on the Senate Foreign Relations Committee, said on Twitter Tuesday that the withdrawal "won't protect American lives or interests -- it leaves Americans sick & America alone.”