TAIPEI - Taiwan will introduce a US$40 billion (S$52 billion) supplementary defence budget to underscore its determination to defend itself, with "significant" new US arms purchases planned, President Lai Ching-te said in a Washington Post op-ed essay.

The move comes as China, which views democratically governed Taiwan as its own territory, has ramped up military and political pressure over the past five years to assert its claims, which Taipei strongly rejects.