Richard Branson's Virgin Group is investing in Hyperloop One, a company developing the super-fast transport system originally dreamed up by Elon Musk.

Hypleroop One is rebranding itself as Virgin Hyperloop One, and Branson is joining the board, the billionaire British investor and entrepreneur announced Thursday on CNBC from London.

Virgin Hyperloop One will focus on a passenger and mixed-use cargo service.

Last month, Hypleroop One raised $85 million in new funding, and that includes the investment from Virgin. Branson refused to provide numbers.

Breaking ground on a commercial hyperloop in two to four years is possible if "governments move quickly," Branson said in a "Squawk Box" interview. So far, no government has approved a plan for a hyperloop system. The Virgin founder also said that building a hyperloop tube above or below ground is "cheaper" and "faster" than a traditional rail network.

The idea of the transport system — conceived in 2013 by Musk, the head of both electric automaker Tesla and SpaceX — works by propelling pods through tubes using magnets reaching speeds akin to those of airplanes.

"As a train owner, " Branson said, "I felt this is something that I want to be able to operate. At the moment our trains are limited to 125 miles an hour." His sprawling Virgin Group empire includes a train network in the U.K., as well as airlines and a business to take tourists into space.

"There are consumers, for instance, that would love to go from London to Edinburgh in roughly 45 minutes. And that will be possible" with a hyperloop, he said. "You can have a pod outside your office that you and your colleagues can jump into. The pod can self-drive to the top of the tunnel. It then goes down the tunnel. It connects up and off you go at 600, 700 miles an hour up to your destination, going faster than an airline."