NEW DELHI, June 1: Indian Foreign Minister Natwar Singh said on Tuesday that his party had disapproved of citing alleged threats from Pakistan and China for Prime Minister Atal Behari Vajpayee to carry out nuclear tests in May 1998.

Mr Singh told his first news conference that his left- leaning United Progressive Alliance (UPA) government would seek a trilateral dialogue with Pakistan and China for a common nuclear doctrine to assure relative security for the South Asian region.

He said details of the proposal would be discussed at a cabinet meeting on security to be headed by Prime Minister Manmohan Singh. "We could have become a nuclear weapons power in 1974.

But we decided not to cross the nuclear threshold, although we had the technology and the expertise," Mr Singh said, recalling the then prime minister Indira Gandhi's decision to carry out India's first ever nuclear test.

When Mr Vajpayee decided to have a string of nuclear tests on May 11 and 13 in 1998, "it became clear to us that Pakistan will follow suit." Mr Singh said: "One of the things that went wrong was the reasons that the prime minister gave about the explosions to US president Clinton, that we were expecting some threat from Pakistan and China.

The letter was leaked to the American press. I asked the prime minister who drafted the letter, he said he did not remember." The Congress would have preferred, that if the tests had to be carried out, then the reason cited should have been that the United states, Russia, France, China, Britain were carrying out tests.

"So India, as an independent country has every right to keep its nuclear technology up to date. So now, if you see our manifesto, we are nuclear powers; so is China.

So I think the three countries should get together and work out a common nuclear doctrine, so that all speculation, all danger disappears. The responsibility of a nuclear power is enormous.

Since 1998 this dimension was absent from our foreign policy, diplomacy, security and defence policy. This is an extremely important part of our security - our security with Pakistan and China. So the priority will be dealt with the greatest seriousness."

An American official said he was surprised by the decision but did not elaborate. Pakistani officials said the issue was too serious to be commented on without a proper discussion.

They recalled that India had earlier ignored the proposal to hold a two-plus-five nuclear dialogue, involving Pakistan and the five recognized nuclear states.