The largest Russian antivirus company, Kaspersky Labs, has informed BBC News that it is quitting the US following the Biden administration's restriction on the company's software's sales and distribution.

Its decision to depart was "sad and difficult," according to Kaspersky, because "business opportunities in the country are no longer viable."

It follows Commerce Secretary Gina Raimondo's statement from last month that Moscow's control over the business constituted a serious threat to US services and infrastructure.

Kaspersky, which had been operating in the US for two decades, has denied the allegations.

"Starting from July 20, 2024 Kaspersky will gradually wind down its US operations and eliminate US-based positions," the firm said in a statement.

Its US website has already stopped selling its antivirus and cybersecurity tools, with a message reading "purchase is unavailable for US customers".

The announcement came after sales and distribution of Kaspersky products were banned in the US.

Ms Raimondo said the US was compelled to take action due to Russia's "capacity and... intent to collect and weaponise the personal information of Americans".

"Kaspersky will generally no longer be able to, among other activities, sell its software within the United States or provide updates to software already in use," the Commerce Department said.

The ruling used broad powers created by the Trump administration to ban or restrict transactions between US firms and technology companies from "foreign adversary" nations like Russia and China.

It effectively barred downloads of software updates, resales and licensing of the products from 29 September, while new business was to be restricted within 30 days of the announcement.

Sellers and resellers who violate the restrictions will face fines from the Commerce Department.

According to the Commerce Department, the Moscow-headquartered multinational company has offices in 31 countries around the world, servicing more than 400 million users and 270,000 corporate clients in more than 200 countries.

At the time Kaspersky said it intended to pursue "all legally available options" to fight the ban, and denied it engaged in any activity that threatened US security.