COVID-19 cases surpassed 500,000 across the world on Thursday, doubling in just over a week as the pandemic accelerates.

The total number of global cases now stands at 510,108 as of 1:30 p.m. ET on Thursday, according to data compiled by Johns Hopkins University. The virus emerged in Wuhan, China, in December. It has since spread to most countries around the world, according to the World Health Organization.

Confirmed COVID-19 cases topped 200,000 last week, and passed 300,000 on Saturday, according to Hopkins data. The virus has infected an additional 100,000 people around the world since Tuesday, when worldwide infections passed 400,000. The virus has now killed more than 22,290 people around the world. Roughly 120,000 people have recovered from COVID-19, according to Hopkins.

China still accounts for the most infections in a single country, according to Hopkins, but Italy is not far behind with more than 80,500 confirmed cases. The U.S. has the third most cases of any country in the world with more than 75,200 confirmed cases, Hopkins' data shows.

WHO officials said Monday that the spread of COVID-19 is picking up speed around the world.

"The pandemic is accelerating," WHO Director-General Tedros Adhanom Ghebreyesus said 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."

On Wednesday, Tedros called the virus "Public Enemy No. 1" and called on countries not to squander any opportunity to save lives with aggressive mitigation measures.

"It's a dangerous virus. We had been saying to the world the window of opportunity is narrowing and the time to act was actually more than a month ago, two months ago," he said. "We have overcome many pandemics and crises before. We will overcome this one, too. The question is how large a price we will pay," he said.