China threatens sanctions on US firms linked to Taiwan warplanes sale

China on Wednesday blasted a huge planned US arms shipment to self-ruled Taiwan and threatened to sanction firms involved in the sale of F-16 fighter jets.

The US State Department on Tuesday approved the transfer of 66 Lockheed Martin-built F-16 fighter jets to Taiwan in a US$8 billion deal, following another huge military hardware sale agreed just last month.

The deals come as ties between Washington and Beijing are already strained by a punitive multi-billion dollar trade war.

"China will take all necessary measures to safeguard our interests including imposing sanctions on the US companies participating in this arms sale to Taiwan," foreign ministry spokesman Geng Shuang told a news briefing.

The sale "is a serious interference in our internal affairs and undermines our sovereignty and security interests", he said. China views Taiwan as part of its territory and has vowed to one day seize it, by force if necessary.

It bristles at any countries that might lend Taiwan diplomatic support or legitimacy.

Secretary of State Mike Pompeo said in a statement Tuesday that President Donald Trump had approved the proposed sale after Congress was notified last week. The F-16s "are deeply consistent with the arrangements, the historical relationship between the United States and China", Pompeo said.

"Our actions are consistent with past US policy. We are simply following through on the commitments we've made to all of the parties."