India's National Security Advisory Board (NSAB) has released a nuclear doctrine which says the country will pursue a policy of a credible minimum nuclear deterrence based on aircraft, ships and mobile land-based missiles.

India's Agni II missile: Could carry nuclear warhead

The statement said: "Autonomy of decision-making in the developmental process and in strategic matters is an inalienable democratic right of the Indian people.

"India will strenuously guard this right in a world where nuclear weapons for a select few are sought to be legitimised for an indefinite future."

Brajesh Mishra, national security adviser to Prime Minister Atal Behari Vajpayee, said India "should remain in a position to retaliate if nuclear weapons are used against us".

US pressure

India tested a series of nuclear devices in May last year, triggering a tit-for-tat response from Pakistan and US-led international sanctions.

The BBC's David Chazan: "India has asserted its place as a strong nuclear power"

Since then, India has come under intense US pressure to sign up to global non-proliferation treaties and ease off on its missile development programme.

But India argues that accords like the Comprehensive Test Ban Treaty are biased in favour of the five recognised nuclear powers - Britain, China, France, Russia and the United States.

Bitter fighting

The authority to release nuclear weapons will reside with the prime minister of the day.

Brajesh Mishra: "This is a draft"

Mr Mishra said the doctrine was a draft and would have to be approved by the new government that will take power after elections in September and October.

"This is a draft...It will have to wait for a new government," Mr Mishra said, adding the draft was being made public to encourage a debate.

The BBC's David Chazan, reporting from Delhi, says the timing of the announcement - just three weeks before elections begin - may be aimed at reinforcing the view that under a BJP-led government, India has established its credentials as a strong nuclear power.

Flashpoint

LK Sharma and Ahmed Rashid discuss today's announcement

Earlier this summer India and Pakistan came close to their fourth war since independence, triggered by bitter fighting in the disputed region of Kashmir.

Continuing border skirmishes are raising concerns in the US that the two new nuclear powers may be marching toward a more serious confrontation.

"Some would say there's a pool of gasoline lying on the ground looking for a match," said Senator Sam Brownback, chairman of the Senate Foreign Relations Subcommittee on Near Eastern and South Asian Affairs.