The United States yesterday said it had approved a $2.4 billion sale of 100 Harpoon coastal defense systems to Taiwan, defying Beijing's anger over a $1 billion missile deal last week. 

The proposed sale of the Harpoon systems "will help improve the security of the recipient and assist in maintaining political stability, military balance... and progress in the region," the State Department said in a statement.

The deal involves 100 Harpoon Coastal Defense Systems (HCDS), which includes 400 RGM-84L-4 Harpoon Block II surface-launched missiles with a range of around 78 miles (125 kilometers).

The missiles, manufactured by Boeing, can be positioned on fixed platforms or mounted on trucks.

Democratic and self-ruled Taiwan lives under constant threat of invasion by authoritarian China, whose leaders view the island as part of their territory. They have vowed to one day seize Taiwan, by force if necessary.

Beijing yesterday said it "firmly opposed" such moves, urging the US to "call off the relevant arms sales plan to Taiwan, so as not to cause further damage to China-US relations and peace and stability across the Taiwan Strait".

Foreign ministry spokesman Wang Wenbin said China would "take proper and necessary measures."