Indian Prime Minister Manmohan Singh arrives on Monday in Washington on the first state visit of the Obama administration – a tribute, both sides say, to the close natural ties between the two giant democracies. But while New Delhi and Washington have moved beyond the chilly relations of the Cold War era, there are still tensions over trade, climate change and Pakistan – and a landmark civil nuclear cooperation deal signed last year has yet to be fully implemented. “It is very easy to get a B+ in US-India relations,” said Jonah Blank, a policy adviser at the Senate Foreign Relations Committee. “But it is time to move beyond the cliches ... and that takes work.” What is the state of the relationship? Both sides say that overall, India and the United States are enjoying their best relationship in decades. India's market reforms in the early 1990s have led to a rapid expansion of trade links, while the 2008 civil nuclear deal that Singh signed with former US President George W. Bush ended the long nuclear isolation imposed on India after it tested an atom bomb in 1974. Political ties have also improved, with the United States looking to India as a global rather than a regional partner on issues including the fight against terrorism. But residual suspicions center on US ally Pakistan – which many in India blame in part for violence such as the 2008 attack on Mumbai – and the fast-growing US relationship with China, another old India rival. What about the nuclear deal? Both sides were jubilant last year when Singh and Bush signed the civil nuclear deal, which US businesses including General Electric Co and Westinghouse Electric Co, a subsidiary of Japan's Toshiba Corp, hoped would open the door to billions of dollars in new reactor agreements. But implementation has hit snags on both sides. India's parliament has yet to debate a new law to limit US firms' liability in case of a nuclear accident. French and Russian competitors in India's nuclear market are state-owned and as such appear far less vulnerable to liability suits. The United States, for its part, has still not signed a nuclear fuel reprocessing agreement with India, which New Delhi sees as central to its long-term energy security. Political analysts say they would be surprised if either of these hurdles was removed in time for Singh's visit – meaning that a deal supposed to underpin the new relationship is likely to remain unrealized for now. So what will the visit accomplish? While there may not be significant progress on the nuclear front, Singh's visit is likely to showcase several other areas of budding US-India cooperation. US officials have promised a new agreement on clean energy, which sources say is likely to be a multimillion dollar clean technology investment fund to develop and deploy low-carbon technologies in India – which still has significant policy differences with Washington on climate change. “It is not a substitute for a full climate change agreement, but it does deliver on technology transfer,” one source with knowledge of the matter said. The two sides may also announce new steps to share security information and to repeat their commitment to expanding educational ties, whereby US educational institutions set up satellite campuses in India. India's growing appetite for arms purchases – budgeted to rise almost 24 percent to $28.9 billion this year – could also figure in the discussions. India is planning one of its biggest ever arms purchases, a $10 billion deal to buy 126 fighter jets, tempting US defense giants such as Boeing and Lockheed Martin Corp to offer their hardware. What about Afghanistan, Pakistan and China? India is likely to pressure the United States to take a tougher line on Pakistan, which it blames for sheltering militants like the ones that attacked Mumbai last year. India has already obtained US endorsement for its aid activities in Afghanistan, where it competes with Islamabad for influence, and New Delhi sees a continued strong US presence there as an important bulwark against Pakistan. Singh is also likely to bring up China, a rival Asian giant which has a long-running border dispute with India. New Delhi bristled recently when the United States and China issued a joint statement that included a line of support for better Indo-Pakistan relations, which was seen as unwelcome outside meddling. As Washington and Beijing negotiate what many expect to be the principal US-Asia relationship, India is anxious to ensure that its interests are not ignored.