Beijing protested to Washington on Tuesday and demanded it cancel a planned US$330 million arms sale to Taiwan, warning that bilateral cooperation would be affected if it went ahead with the deal. The proposal announced by US defence officials on Monday comes as relations between Beijing and Washington are already strained. Taiwan said the deal would help boost the self-ruled island’s defences, but Chinese foreign ministry spokesman Geng Shuang said Beijing had lodged stern representations with the US about the plan. “We urge the US side … to immediately cancel this deal and cut off military ties with Taiwan to avoid doing serious damage to China-US relations, peace and stability in the Taiwan Strait and cooperation between US and China in important areas,” Geng told a regular press briefing on Tuesday, without elaborating. China’s defence ministry also delivered a similar warning. The proposal will go before the US Congress and covers spare parts for F-16, C-130 and F-5 indigenous defence fighter jets, and other aircraft systems. China’s new fighter jet ‘targeting Taiwan’ may soon be combat ready “This proposed sale will contribute to the foreign policy and national security of the United States by helping to improve the security and defensive capability of the recipient, which has been and continues to be an important force for political stability, military balance and economic progress in the region,” the Pentagon’s Defence Security Cooperation Agency said in a statement. Beijing regards Taiwan as a breakaway province to be reunited with the mainland, by force if necessary. It has previously warned Washington against selling weapons to Taiwan and establishing military relations with the island, and remains locked in a trade war with the US. Taiwan’s Presidential Office welcomed the move. “We greatly appreciate that the US government takes note of the national security of Taiwan and its commitments to firmly abide by the Taiwan Relations Act and six assurances [regarding US policy towards the island],” office spokesman Alex Huang said. Three loud and clear messages from Taiwan’s military exercise He said the latest weapons sale could also help boost the island’s confidence in facing security challenges from Beijing, and strengthen its ability to ensure cross-strait and regional peace and stability, thereby improving cross-strait relations. “We will continue to increase our investment in national defence, boost our defence industry and technology development, and closely cooperate and communicate with the US on various security issues and agendas,” Huang said. The six assurances, issued by former US president Ronald Reagan in 1982, include the US pledging not to set a date for ending arms sales to Taiwan, not to hold prior consultations with Beijing on arms sales to Taipei, and not to play a mediation role between the two sides of the Taiwan Strait. The planned arms deal was announced days after the US State Department imposed sanctions on a key Chinese military unit and its director for buying Russian fighter jets and surface-to-air missiles – a move that inflamed tensions amid the spiralling trade war. Chinese analysts said the latest moves showed all aspects of China-US relations – from trade to security – were under strain, and Beijing was likely to retaliate. “Beijing is much more confident now, and it’s in a better position to take countermeasures than it was before,” said Shen Dingli, director of the Programme on Arms Control and Regional Security at Fudan University in Shanghai. “The US has to work with other countries, including China, in areas like counterterrorism, non-proliferation, anti-money laundering and infectious disease control,” he said. “It can’t expect China to cooperate whenever it makes a demand while it is hurting China’s interests.” This year’s arms deal is relatively small compared with previous years and it involves maintenance and spare parts, which will not make much difference to the power balance across the strait, said Pang Zhongying, a foreign affairs expert at the Ocean University of China. But he said it was the timing of the announcement that had infuriated Beijing, coming so soon after the sanctions were imposed. This will be the second US arms deal to Taiwan under the administration of US President Donald Trump after it agreed to sell a US$1.4 billion weapons package, mainly missiles, to the island last year. Hong Kong-based military commentator Song Zhongping said there was likely to be a much bigger and more sensitive deal announced next year – possibly including the powerful M1A2 tanks that Taiwan has asked for – after the US Congress passed the National Defence Authorisation Act, pledging to sell more weapons to the island. “US arms sales to Taiwan are a long-term matter. The smaller deal this year means they could be building up to challenge Beijing with something bigger in the future,” Song said.