Beijing on Monday said it would impose sanctions on two American defence companies in retaliation to the latest US arms sale to Taiwan . Chinese foreign ministry spokesman Wang Wenbin told reporters that Lockheed Martin and Raytheon Technologies would be subject to sanctions for their “long-term involvement in US arms sales” to the island. The US$100 million deal – approved by the US two weeks ago and aimed at upgrading Taiwan’s Patriot missile defence system – was a serious infringement of China’s sovereignty and security interests, Wang said. “China once again urges the US government to abide by the one-China principle and the provisions of the three Sino-US joint communiques, and to stop arms sales to Taiwan and US-Taiwan military ties,” Wang said, referring to statements that included an agreement by the US to gradually reduce arms sales to the island. “China will continue to take all necessary measures to firmly safeguard its sovereignty and security interests in the light of developments in this situation.” Wang said the “countermeasures” were in accordance with China’s anti-sanctions law. The law, which was passed in June , provides legal backing for Beijing to take retaliatory measures against foreign individuals and entities perceived to be interfering in China’s internal affairs, including by seizing assets and imposing business restrictions. The foreign ministry spokesman did not give further details of the sanctions or how they would be carried out. The two US defence firms do not do any business with mainland China. Beijing views democratically governed Taiwan as a breakaway province to be taken under its control, by force if necessary, and has ramped up diplomatic and military pressure on the island in recent years. It is angered by US weapons sales to Taiwan, which Beijing says undermine its sovereignty. Washington is required under US law to provide Taiwan with the means to defend itself. Beijing previously said sanctions would be imposed on US firms including Lockheed Martin, Raytheon and Boeing Defence as well as individuals involved in a US$1.8 billion arms deal to Taiwan in 2020. No details of those sanctions were given. The latest US arms deal – the second approved by the Joe Biden administration – includes equipment and services to support participation in the Patriot International Engineering Services Programme and Field Surveillance Programme for five years. Chinese ambassador warns US its strengthened Taiwan ties could lead to war It comes as tensions are soaring across the Taiwan Strait, with the People’s Liberation Army sending warplanes into the island’s air defence identification zone on an almost daily basis. Last week, Taiwan’s defence ministry said a PLA Ka-28 anti-submarine helicopter was seen entering the air defence zone for the first time. Meanwhile Taiwan – which lives with the threat of invasion by Beijing – plans to stage live-fire drills next month at several islets under its control, including two close to the Chinese mainland, to test the combat readiness of its forces.