Amid efforts by the Bush administration to push the Indo-US civil nuclear deal through the Congress, Washington Friday asked India to "further define" its 'minimum credible deterrent' in the nuclear field, saying it was "absolutely necessary" for decreasing tensions in Asia.

US Assistant Secretary of State for South Asia Richard Boucher also said that New Delhi and Islamabad should work out "mutual understandings" to build confidence in both conventional and nuclear areas.

"As in the past, we continue to look to India for leadership in stabilising nuclear and defence relations with its neighbours," he said delivering a talk on 'The US-India friendship: Where we were and where we are going' here.

He said the Bush administration, like the previous US governments, have "pushed for India to further define its 'minimum credible deterrent' (in nuclear field) and we continue that today."

Noting that Washington understood the complexity of this task having spent 40 years in discussions with the former Soviet Union over the nuclear programmes of the two countries, he said the US realises that such discussions are "complicated by China's intentions and by Iran's energetic pursuit of technologies that underlie nuclear weapons.

"Nevertheless, we see this as an absolutely necessary step toward decreasing tensions in Asia," Boucher said.

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