A top US official has arrived in India for talks expected to focus on a landmark nuclear co-operation agreement between the two countries.
Burns is expected to meet top Indian officials
US Undersecretary of State Nicholas Burns will meet Indian Foreign Secretary Shiv Shankar Menon and other senior Indian officials.
The landmark deal allows the US to sell civilian nuclear technology to India for the first time in three decades.
The agreement is expected to soon be ratified by the US Congress.
Critics of the accord fear it could harm non-proliferation efforts.
Under the deal, energy-hungry India will get access to US civil nuclear technology and open its nuclear facilities to inspection.
The US Senate and the House of Representatives, the lower house of US Congress, have already voted to pass the controversial deal.
The Senate bill and a version passed by the House of Representatives must now be reconciled and approved by US President George W Bush before the legislation can take effect.
Correspondents say that once the legislation is approved, the initiative will overturn decades of US anti-proliferation policy.
India wants to rid itself of US sanctions imposed in 1998
But several obstacles loom before the two countries can begin trade in civilian nuclear materials.
India would need to get approval for the deal from the Nuclear Suppliers Group, an assembly of nations that export nuclear material.
Delhi would also need to negotiate a safeguard agreement with the UN nuclear watchdog, the International Atomic Energy Agency (IAEA).
There is also some concern about the transfer of missile technology to Iran by at least two Indian firms, recently black-listed by the US government.
The agreement was finalised during Mr Bush's visit to India in March.