BEIJING: China vowed on Monday to “take countermeasures” against companies involved in arms sales to Taiwan after the United States approved a $300-million deal to beef up the self-ruled island’s defences.

China views Taiwan as part of its territory and has pledged to seize it one day, while the US Congress requires the supply of weapons to the self-governing democracy for its defence. The US State Department last week approved an arms package that both sides said would strengthen Taipei’s joint battle command and control system.

Beijing hit back on Monday, saying it would take “resolute and strong measures to defend its national sovereignty and territorial integrity”.

“We will take countermeasures against relevant enterprises involved in arms sales to Taiwan,” foreign ministry spokesman Wang Wenbin said at a regular news briefing, without giving details.

The United States “should stop the dangerous trend of arming Taiwan, stop creating tensions in the Taiwan Strait, and stop indulging and supporting the separatist forces of Taiwan independence in their quest for achieving independence by force,” he added.

“China will eventually reunify, and indeed must reunify.”

Beijing has ratcheted up the pressure on Taiwan since independence-leaning President Tsai Ing-wen took power there in 2016.

It regularly sends warplanes and vessels near the island, whose defence ministry recently also reported several sightings of balloons from the mainland.

Both Washington and Taipei have warned Beijing not to seek to influence presidential elections in Taiwan next month.