The US government has notified Congress of plans to supply Taiwan with arms worth more than $6bn (£3.4bn).
The sales include advanced interceptor missiles, Apache helicopters and submarine-launched missiles.
Correspondents say the decision is likely to anger China, which regards Taiwan as its territory and opposes US military support of the island.
The move could also complicate efforts to get North Korea, an ally of Beijing, to end its nuclear programme.
The US Defence Security Co-operation Agency (DSCA) said the sales would “help improve the security of the recipient and assist in maintaining political stability, military balance and economic progress in the region”.