Attempts by India and the US to reach a historic nuclear co-operation deal will be at risk if they are unable to find common ground before President George W. Bush's visit to New Delhi in early March, US officials have said.

Talks last week between Nicholas Burns, US undersecretary of state for political affairs, and Indian officials ran into serious difficulties, raising doubts over whether the US administration would have a deal to run past key US Congress decision-makers before the visit.