Beijing will impose sanctions on Lockheed Martin after the US approved a deal that would allow Taiwan to upgrade its Patriot missile defences. “The Chinese side has decided to take the necessary measure by imposing sanctions on Lockheed Martin Corporation, which is the chief contractor in the arms deal,” foreign ministry spokesman Zhao Lijian told a news conference in Beijing on Tuesday. Last week the State Department approved a US$620 million package for the self-ruled island to extend the operational life of its US-supplied Patriot Advanced Capability-3 (PAC-3) missiles. Identifying Lockheed Martin as the main contractor, the State Department said that the “proposed sale serves US national, economic and security interests by supporting the recipient’s continuing efforts to modernise its armed forces and to maintain a credible defensive capability.” Taiwan would “use this capability as a deterrent to regional threats and to strengthen homeland defence”, it noted. US sends surveillance aircraft to watch Chinese coastline as Taiwan starts major military exercise In May the US also approved the sale of US$180 million worth of advanced torpedoes and related equipment for Taiwan. Zhao said Beijing had lodged solemn representations with Washington about the planned deal. “We firmly oppose to the US arms sales to Taiwan and urge the US to earnestly abide by the one-China principle and the three China-US joint communiqués [from 1972-1982 upholding the one-China principle] and stop arms sales to and military ties with Taiwan, lest it should further harm China-US relations and cross-straits peace and stability,” he continued. He stressed the sanctions against Lockheed Martin were in line with China’s national interests. He did not say what form the sanctions would take and how and when they would be carried out. Beijing considers Taiwan a wayward province that must be returned to the mainland fold by force if necessary. It has stepped up its attempts to intimidate the island since Tsai Ing-wen, of the independence-leaning Democratic Progressive Party, was elected Taiwan’s president in 2016 and refused to accept the one-China principle. Taiwan welcomed the US approval of the missile upgrade deal, saying it would “help us to continue our defensive capability and ensure peace in the Taiwan Strait and security in the region”. Presidential spokesman Alex Huang stressed the deal would help Taiwan to “counter rising military threats from Beijing in the Taiwan Strait and regionally”. Taiwan’s military tests defences against mainland China invasion in annual war games Once confirmed, the arms sale will be the seventh approved by the Trump administration to Taiwan. Taiwan’s military has said these deals fully demonstrate not only the US commitment to Taiwan’s defence, but also the security partnership between Taipei and Washington. Tensions in the region have been mounting as mainland China, the United States and Taiwan have all boosted their military deployment and staging war games. On Monday, Taiwan’s military began five days of live-fire exercise to prepare for any invasion from the mainland. Meanwhile, the PLA conducted a drill near the disputed Paracel Islands at the start of the month, while the US held its own exercises in the South China Sea. Additional reporting by Catherine Wong