Lockheed Martin is reportedly the major contractor for Washington's $620 million package to upgrade Taiwan's Patriot surface-to-air missiles system.
China will impose sanctions on US defence group Lockheed Martin, a decision which followed Washington's approval of a potential $620 million upgrade package for missiles to Taiwan.
The possible foreign military sale involves Patriot Advanced Capability-3 missiles and would be the island's latest purchase from the US to boost its defence capabilities as China grows in strength.
China "firmly opposes US arms sales to Taiwan", foreign ministry spokesman Zhao Lijian told a regular briefing on Tuesday, urging Washington to abide by the concept that Taiwan is part of "one China".
Zhao added that the US should "stop arms sales to Taiwan and cut military ties with it, so as not to further harm China-US relations and peace and stability across the Taiwan Strait".
He said China's move to hit Lockheed Martin with sanctions was "to safeguard its national interests".
Taiwan condemns sanctions
Taiwan's foreign ministry countered that it "strongly condemns" China's "irrational outbursts and crude threats" over the US announcement.
"It is necessary for Taiwan to acquire military equipment from abroad and to strengthen its self-defence capabilities to maintain peace in the Taiwan Strait," said spokeswoman Joanne Ou in a statement.
"It is also a legitimate action to defend our national sovereignty and democratic system," she added.
Taiwan Defence Minister Yen Teh-fa, visiting troops during the annual Han Kuang military exercise, said they needed to be strong in the face of "all sorts of threats and provocations" from China.
"This tells our people and the Communists that we have the confidence and ability to protect our people and homeland, and defend the country's security," his ministry cited him as saying.
While Taiwan's military is well-trained and well-equipped with mostly US-made hardware, China has huge numerical superiority and is adding advanced equipment of its own such as stealth fighters and new ballistic missiles.
Tensions between US and China
The US, like most countries, has no official diplomatic ties with Taiwan, but is bound by law to provide the democratic island with the means to defend itself.
Last year, China threatened sanctions on US firms linked to a sale of warplanes to Taiwan as well, calling the move a serious interference in its internal affairs.
Tensions between the US and China have been increasingly strained as the two sides tussle on various fronts, ranging from the origins of the coronavirus pandemic and China's policies in Hong Kong, Tibet and Xinjiang.
Taiwan has been ruled separately from the mainland since 1949, although Beijing views the island as part of its territory and has vowed to seize it by force if necessary.