The State Department said on Tuesday it had Ok'd Taiwan's purchase of four "weapons ready" remotely piloted aircraft and related equipment. The move is likely to infuriate China, which regards Taiwan as a renegade province and has reacted angrily to previous weapons sales' announcements to the island.

"This proposed sale serves US national, economic and security interests by supporting the recipient's continuing efforts to modernise its armed forces and to maintain a credible defensive capability," it said. "The proposed sale will help improve the security of the recipient and assist in maintaining political stability, military balance, economic and progress in the region."

It said the sale would improve Taiwan's defence by bolstering its intelligence, surveillance and reconnaissance capabilities and could help deter military action against it.

Just last week, the administration approved plans for a USD 2.37 billion sale of Harpoon missile systems to Taiwan. That came hours after Beijing had announced sanctions on US defence contractors, including Boeing, the lead contractor on the Harpoon deal, over a previous weapons deal.

China's ruling Communist Party claims Taiwan, which split with the mainland in 1949 during a civil war, as part of its territory and has threatened to invade. Washington promised in the 1980s to reduce and eventually end weapons sales to Taiwan but insists its dispute with Beijing must be settled peacefully.

Chinese-US relations have plunged to their lowest level in decades amid disputes about security, technology, the coronavirus pandemic and human rights.

Taiwan has long been an irritant in relations. Washington has no formal relations with the island's democratically-elected government but is its main ally. US law requires the government to ensure Taiwan can defend itself. Weapons sales to the island have increased in quantity and quality.