YouTube on Thursday started rolling out an early version of its Shorts quick-clip feature in the United States, ramping up its challenge to TikTok.

The popularity of YouTube Shorts soared during testing in India, and it has been racking up more than 6.5 billion views a day by people tuning in overall, according to product chief Todd Sherman of the Google-owned video service.

"We're introducing our YouTube Shorts Beta to the United States starting today, as we continue to build the experience alongside our global community," Sherman said.

"We plan to introduce more features as we continue to build Shorts alongside creators and artists."

YouTube is also working on ways for people to make money from audiences at Shorts, according to Sherman.

The new service is the latest to challenge the fast-growing and popular Chinese-owned video app TikTok.

Netflix early this month added a "Fast Laughs" feature to its iPhone app, serving up comic clips in rapid fire, in a move taking on the TikTok.

Facebook-owned Instagram responded to TikTok's popularity with their own short video format called Reels last August.

And last November, Snapchat launched Spotlight, a public feed of content produced by users.