The U.N. Secretary General says the world's nations must work cooperatively in the fight against COVID-19, "or else we will be defeated by the virus."

Antonio Guterres said in an interview Friday on the PBS News Hour he is "worried" that if the virus gets a foothold in Africa, millions of people will die. "Africa is a continent with very little capacity to respond and I am extremely worried."

The U.N. announced late Friday that 86 members of its staff have the coronavirus.

The United States is now regarded as the epicenter of the worldwide coronavirus outbreak, which originated in China.

Early Saturday, the U.S. had 104, 837 confirmed coronavirus cases, compared with 81,947 in China, according to the Johns Hopkins Coronavirus Resource Center. Italy, the epicenter of the virus in Europe, had 86,498 confirmed cases. The global tally of confirmed cases is 601,478.

A scathing article in the British medical journal Lancet says that the National Health Service was "wholly unprepared" for the coronavirus outbreak, and that it is hard to understand why.

Richard Horton, editor of Lancet, said NHS officials had written an article for Lancet in January saying the virus "could be about to become a global epidemic ... for health protection within China and internationally ... preparedness plans should be readied for deployment at short notice, including securing supply chains of pharmaceuticals, personal protective equipment, hospital supplies, and the necessary human resources to deal with the consequences of a global outbreak of this magnitude."

Britain has 14,751 virus cases, according to Johns Hopkins.

U.S. President Donald Trump is ready to have the National Guard and the Reserves join in the fight against COVID-19, according to a Defense Department statement Saturday.

The people who are called up would be "persons in headquarters units and persons with heightened medical capabilities."

According to the statement, officials with the Defense Department and the Department of Health and Human Services would talk with state officials before deploying the National Guard Reserve Component Services.

Trump signed a $2.2 trillion stimulus measure Friday to bolster the economy that is reeling in the aftermath of the coronavirus.

Also Friday, Trump said he used government powers under the Defense Production Act to compel General Motors to manufacture ventilators to help COVID-19 patients as the United States became the first country in the world to surpass 100,000 coronavirus cases.

"GM was wasting time. Today's action will help ensure the quick production of ventilators that will save American lives," Trump said in a statement.

GM, however, released a statement Friday saying it had been working since last week with Ventec Life System to mass produce critical care ventilators for the coronavirus pandemic.

"Since Friday, March 20, Ventec and GM teams across manufacturing, engineering, purchasing, legal and others have been tirelessly and seamlessly working together to create and implement a plan for immediate, scaled production of critical care ventilators," the statement said.