US intelligence chiefs have been briefing Silicon Valley tech execs about the possible dangers of doing business in China, according to a report from the Financial Times.

The briefings include warnings about the threat of cyber attacks and the theft of intellectual property, and have been held with groups including tech companies, universities, and venture capitalists in California and Washington.

The meetings are the latest example of the US government’s increasingly combative stance towards China. In a statement given to the FT, Republican senator Marco Rubio — one of the politicians who organized the briefings — outlined the rationale behind them.

“It’s important that US companies, universities, and trade organizations understand fully that threat.”

“The Chinese government and Communist party pose the greatest long-term threat to US economic and national security,” said Mr Rubio. “It’s important that US companies, universities, and trade organizations understand fully that threat.”

Those giving the briefings include high-level figures in the US intelligence community such as Dan Coats, director of national intelligence. The meetings also reportedly include the sharing of classified information — an unusual level of disclosure.

The FT reports that the briefings began last October. Since then, the trade war between the US and China has escalated dramatically. The most significant intervention came last week, with the White House announcing that US companies will be blocked from buying telecommunications equipment from certain foreign companies including China’s Huawei.

The Trump administration says this ban is necessary to counter the threat of surveillance and spying from Chinese-made equipment. But the ban is likely to have a big affect on consumers around the world, especially with the news that Google will no longer be able to supply the full version of its Android mobile operating system to Huawei.