De Blasio: New York at the heart of national crisis

New York's Mayor Bill de Blasio warned on Tuesday the city was in a "battle" to stop the spread of the coronavirus.

At a briefing in City Hall, the mayor said New York was "the epicenter of this crisis for this nation."

"People are recognizing and dealing with this new reality. Making the tough choices and the sacrifices," De Blasio said.

On Monday, the U.S. saw its biggest jump yet in the death toll from the virus, with more than 700 American deaths now attributed to COVID-19.

The U.S. is now more than a week into an unprecedented 15-day effort to encourage all Americans to drastically scale back their public activities.

While the worst outbreaks are concentrated in certain parts of the country, such as New York, experts warn that the highly infectious disease is certain to spread.

For most people, the new coronavirus causes only mild or moderate symptoms, such as fever and cough.

For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia.

The pandemic has infected more than 417,000 people and killed over 18,600.

More than 107,000 people have recovered so far, mostly in China.