The fate of a historic civil nuclear deal between the US and India will loom over George W. Bush and Manmohan Singh when they meet on the sidelines of the G8 summit in Germany next month amid continuingdifferences over New Delhi's right to test nuclearweapons and reprocess fuel.

Nicholas Burns, US undersecretary of state, is expected to visit New Delhi next week in a last-ditch attempt to narrow outstanding differences ahead of the G8 meeting, a move that analysts said would underscore the fragile state of the deal.