Two top American nuclear experts have said that India's nuclear strategy is experiencing a shift as it is now modernising its nuclear arsenal with a focus on China rather than its traditional rival Pakistan, Times of India reported.

"India is estimated to have produced approximately 600 kilograms of weapon-grade plutonium sufficient for 150–200 nuclear warheads," read an article by American nuclear experts Hans Kristensen and Robert Norris published in digital journal Bulletin of Atomic Sciences' July/August issue.

"While India has traditionally been focused on deterring Pakistan, its nuclear modernisation indicates that it is putting increased emphasis on its future strategic relationship with China," they said.

"The two-stage, solid-fuel, rail-mobile Agni-2, an improvement on the Agni-1, can deliver a nuclear or conventional warhead more than 2,000 km," the article said, adding that the targeting of the arsenal is "probably focused on western, central, and southern China."

The article stated that India was also developing Agni-3, 4 and 5, adding that the extra range of Agni-5 will allow "the Indian military to establish Agni-5 bases in central and southern India, further away from China."