The sale is comparatively small in scale and does not expand the range of US weaponry to Taiwan, but comes as the United States and China move delicately to stabilize their turbulent relationship.

In a notification to Congress, the State Department said it would sell $332.2 million in 30mm ammunition and related equipment to Taiwan and $108 million in spare and repair parts for wheeled vehicles and weapons.

The sales will help Taiwan "maintain a credible defensive capability" but "will not alter the basic military balance in the region," it said.

It "will help improve the security of the recipient and assist in maintaining political stability, military balance and economic progress in the region," it said.

Taiwan's defense ministry on Friday welcomed the planned sale for "providing the need for enhancing our defense capacity as well as maintaining regional stability," it said in a tweet.

Congress has the right to reject the sale but such a move is highly unlikely, with lawmakers pushing for the United States to go further and directly provide weapons to Taiwan rather than approving its purchase requests.

In a decades-long policy, the United States sells weapons to Taiwan to ensure its self-defense but only recognizes Beijing.

China, which claims the self-governing democracy as its own territory and has not ruled out seizing it through force, detests any hint of diplomatic relations between Taiwan and other governments.

- 'Stop endangering peace' -

Chinese foreign ministry spokeswoman Mao Ning reiterated China's "firm opposition" to Washington supplying weapons to the island.

"The United States should... stop creating new causes of military tension in the Taiwan Strait, and stop endangering peace and stability in the Taiwan Strait," she told reporters Friday.

Earlier in June, US Secretary of State Antony Blinken paid a rare visit to Beijing in which his hosts vowed no compromise on Taiwan.

But the two sides voiced hope at keeping up communication to keep tensions from boiling over.

Twice in the past year, China has carried out huge military exercises in waters around Taiwan in response to gestures of support by top US lawmakers.

On Friday, Taipei said it detected five Chinese warships and 24 Chinese warplanes around the island, of which 11 crossed the median line of the Taiwan Strait.