A new Omicron subvariant is spreading in the United States, and has accounted for nearly 10 per cent of new weekly Covid-19 cases reported across the country, according to data updated by the US Centers for Disease Control and Prevention (CDC).

The subvariant XBB.1.16, referred to as "arcturus", has been added by the CDC to its variant tracker, Xinhua news agency reported.

The percentage is expected to increase in the coming weeks, and it may become the next dominant coronavirus strain in the country, experts warned.

The highly transmissible Omicron subvariant XBB.1.5 remains the dominant strain in the US and accounted for about 73.6 per cent of new Covid-19 cases this week, CDC data showed.

The World Health Organization is monitoring XBB.1.16, which is contributing to a recent surge of Covid-19 cases in India. [IANS/NS]