New Delhi, April 7: The US today asked India to define its “minimum credible deterrent” as it was important to defuse tension in the region.

The US assistant secretary of state for south and central Asia, Richard Boucher, who met Indian officials, said defining the minimum credible deterrent was crucial in the wake of China’s intentions and Iran’s pursuit of nuclear technology. Delhi will have to specify the number of nuclear weapons it wants for security.

“We look not only to India, but to Pakistan, to work out mutual understandings to build confidence in both conventional and nuclear areas,” he said, delivering a talk on “US-India friendship: Where we were and where we are going”.

Boucher said the Bush administration was not disturbed by the “noisy and messy” debate on the Indo-US nuclear deal and hoped the pieces of the puzzle would fall in place.

He said questions have been raised by opinion makers on the nuclear deal but the momentum has been positive. Despite a lot being said against the deal, no one is opposed to improving ties with India, he added.

Though the deal has been sealed, several aspects remain to be settled. But Boucher said there was no question of renegotiating the pact.

Boucher met foreign secretary Shyam Saran and the heads of territorial divisions of Eurasia, Pakistan-Afghanistan-Iran and Bangladesh-Sri Lanka-Maldives.

His visit comes within days of his boss Condoleezza Rice testifying before both Houses of the US Congress in support of the pact that seeks to change international nuclear rules for India.

At a function organised by the Confederation of Indian Industry after a hectic day of meetings that continued over lunch, Boucher chose to clear doubts about Washington’s Nepal policy.

He said there was no difference between India and the US on Nepal. “We are on same wavelength.”