The Trump administration has announced a huge arms sale worth around $11bn (£8.2bn) to Taiwan, which includes advanced rocket launchers, self-propelled howitzers and a variety of missiles.

This package, which still needs to be approved by the US Congress, will be the second arms sale to Taiwan since Donald Trump returned to the White House in January.

China, which sees self-governed Taiwan as a breakaway province, has steadily ramped up pressure over the island with military drills and regular incursions into its waters and airspace.

Taiwan’s defence ministry thanked the US on Thursday, saying the deal would help the island in “rapidly building robust deterrence capabilities”.

The US has formal diplomatic ties with Beijing rather than Taiwan and has walked a tight diplomatic rope for decades. But it remains a powerful ally of Taiwan’s and the island’s biggest arms supplier.

China has not commented on this announcement, but the foreign ministry warned last month that an earlier deal – a $330m sale of fighter jets and other aircraft parts in November – “gravely infringed” upon China’s sovereignty and security.

The latest package features High Mobility Artillery Rocket Systems (Himars) worth $4bn and self-propelled howitzers worth $4bn, according to the US Defense Security Cooperation Agency, which announced the details late on Wednesday.

The size of this sale, if it goes through, dwarfs the 19 rounds of arms sales totalling $8.38bn during the previous administration under Joe Biden.

In his first term, Trump had approved arms sales to Taiwan totalling $18.3bn – the largest package was worth $8bn.

The US State Department said this deal serves Washington’s interests “by supporting [Taipei’s] continuing efforts to modernise its armed forces and to maintain a credible defensive capability”.

China has long vowed to “reunify” with Taiwan and has not ruled out the use of force to take it.

It is a threat that Taiwan is increasingly taking seriously. It plans to boost defence spending to more than 3% of its gross domestic product next year and up to 5% by 2030.

In October, President Lai Ching-te announced the building of a dome-like air defence system to guard against “hostile threats”, without mentioning China by name.

China has grown increasingly assertive in the region, often rattling neighbours with unusual moves – in June, Japan protested following an unprecedented naval drill by Chinese aircraft carriers in the Pacific.

More recently the two countries have been sparring over the Japanese prime minister’s suggestion that Japan could deploy its own self-defence force if China attacks Taiwan.

Tensions escalated this month as boats from both sides faced off near disputed islands, and Chinese fighter jets locked radar on Japanese aircraft.