World Health Organization (WHO) has deployed a team to China to launch an investigation into the origin of the new coronavirus pandemic which has infected more than 12 million people across the globe and left over 550,000 dead.

In a statement on Friday, the UN agency announced that a two-member team, with expertise in animal health and epidemiology, left for China and would work with Chinese scientists to determine the scope and itinerary of the investigation.

“We know it’s very, very similar to the virus in the bat, but did it go through an intermediate species? This is a question we all need to be answered,” said WHO spokeswoman Margaret Harris in a news briefing but declined to name the experts.

The new coronavirus is believed to have emerged in a wholesale market in the central Chinese city of Wuhan in December last year after jumping the species barrier from the animal kingdom to infect humans.

Separately, WHO Director-General Tedros Adhanom Ghebreyesus later said at a press conference that the two experts at the time were en route to China “to meet with fellow scientists and learn about the progress made in understanding the animal reservoir for COVID-19 and how the disease jumped between animals and humans.”

He further said that the investigation would help lay the groundwork for the WHO-led international mission into the origins of the new coronavirus, which causes COVID-19, a contagious respiratory disease.

Earlier this week, the United States, which used to be WHO’s largest donor, notified the UN agency that Washington was withdrawing in a year’s time after accusing the agency of being too close to China and not doing enough to question Beijing’s actions at the start of the crisis.