The United States now has more confirmed coronavirus cases than Italy and China, making it the country with the largest outbreak in the world.

The total number of cases in the U.S. reached 82,404 Thursday evening, eclipsing China's 81,782 cases and Italy's 80,589, according to data compiled by Johns Hopkins University.

The virus emerged in Wuhan, China, in December. It has since spread to more than half a million people in almost every country around the world and continues to pick up speed, the World Health Organization warned earlier this week.

"The pandemic is accelerating," WHO Director-General Tedros Adhanom Ghebreyesus said Monday at a press briefing from the organization's Geneva headquarters. "It took 67 days from the first reported case to reach 100,000 cases, 11 days for second 100,000 cases, and just four days for the third 100,000 cases."

Confirmed U.S. cases passed 5,000 last week. At the beginning of the month, there were roughly 100 confirmed cases in the U.S.

The number of confirmed cases likely underestimates the true number of infections across the country, officials have acknowledged. Testing in the U.S. has been hampered by delays and a restrictive diagnostic criteria that limits who can get tested.