Both countries regularly test ballistic missiles and other advanced military hardware and Pakistan conducted tit-for-tat nuclear explosions in 1998.

Pakistani defence strategists say the majority of India's arsenal is Pakistan-specific, and the stockpiles are growing amid New Delhi's increasing desire for military hegemony in the region.

The two neighbours have fought three wars since gaining independence from Britain in 1947.

Relations between them are currently under strain over India's demands that Pakistan act firmly against the proscribed Lashkar-e-Taiba terrorist organisation, which is believed to be behind the November 2008 attacks in Mumbai, which killed 170 people.