Zipline, a California-based robotics company that has made a name for itself delivering blood by drone in Rwanda, has just announced plans to operate its services in Tanzania by early next year.

In an interview with The Verge, Zipline co-founder and chief executive Keller Rinaudo said that the company plans to work with the Tanzania Ministry of Health and the country’s Medical Stores Department to open four distribution centers in Tanzania over the next four years, with the intent to deliver blood via drone to over a thousand public health facilities in the country.

Zipline also wants to expand services in Tanzania to include on-demand delivery of other medical supplies, things such as emergency vaccines, HIV medications, and anti-malaria drugs. Emergency restocks “might not sound that exciting,” Rinaudo said, but “that’s the real goal, delivering all of these products. It’s been a problem for over a hundred years, but it’s a problem that global health experts have been trying to solve for the past 50 years.”

Zipline first launched its services in Rwanda in the fall of 2016, calling it the world’s first national drone delivery service. The company has raised more than $35 million in venture capital funding to date.

Since last October, Rinaudo said, Zipline has completed 1400 commercial flights and delivered 2600 units of blood, a quarter of which were for emergency services. (These are numbers Zipline hasn’t shared previously.)

The company designs and builds its own 25-pound drones, called Zips, that can fly up to 150 kilometers per charge and carry up to 1.5 kilograms of blood. But the real value lies in Zipline’s software and logistics, not the hardware. Health professionals can use Zipline to order supplies via mobile phones — sometimes using WhatsApp, Rinaudo said — and can receive the necessary supplies within 30 minutes, on average. Fifty percent of the supplies are going to mothers with postpartum hemorrhaging, and 30 percent is going toward kids under the age of five who have severe anemia due to malaria.

This is not only vital in emergency situations, but it also helps eliminate waste: Rinaudo claimed that “zero units” of blood have expired in the Rwanda health centers that have been relying on Zipline over the past several months.

For its Tanzania launch, Zipline says it will partner with the Human Development Innovation Fund, the Bill & Melinda Gates Foundation, and the Saving Lives at Birth initiative to conduct research on the Zipline’s impact on the region.

Zipline has talked before about testing its services in the US, where it’s based, but so far this hasn’t happened in any official capacity. The regulatory environment for drones here is still too challenging, Rinaudo said, something he elaborated on earlier this year in a Recode podcast interview. Still, he’s hopeful, adding that the US government is “looking at what’s happening in Rwanda and is excited.”

“The cool thing is now that we’ve shown that this can be done safely, operate at national safety levels,” Rinaudo said. “There’s a lot of evidence and data that we can show.”