US arms deal angers China

China has threatened to impose sanctions on US arms firms and cut co-operation with Washington unless it cancels a $6.4bn (£4bn) arms sale to Taiwan.

In an unprecedented move yesterday signalling China's growing global power, Beijing bitterly denounced the Obama administration's announcement on Friday that it planned to sell the package of weapons to Taiwan, which Beijing views as an illegitimate breakaway province. The dispute deepens the rifts between Beijing and Washington, also at odds over trade, currency, Tibet and the internet. Beijing said it would retaliate against US companies that sold arms to Taiwan, a break with past practice. China's commercial reprisals have in the past been informal.

The proposed sales include Black Hawk helicopters, Patriot anti-missile missiles, two refurbished Osprey-class minehunting ships and Telemetry missiles built by McDonnell Douglas, a subsidiary of the aircraft manufacturer Boeing.