Indian Prime Minister Narendra Modi is back in Washington this week - to meet with the US president and American business leaders. He is also due to make a rare address to the US Congress.

Indian Prime Minister Narendra Modi comes to the United States expecting to close a deal for deeper defense cooperation begun by his defense chief in April.

That's when US Defense Secretary Ashton Carter and Indian defense minister, Manohar Parrikar announced a deal in principal which would facilitate greater interoperability between the Indian and American navies. It's a measure Beijing is watching closely. 

"This just facilitates the sharing of logistics on the ground when you already give an agreement of an American ship docking at port or something like that. Or when you engage in exercise or something but still any time you have a tangible marker like this, and I'm sure that countries that look at this with some concern like China they will point out that they're concerned about the growth in the US- India security relations," said Rick Rossow from Center for Strategic & International Studies.

New Delhi also sees Washington as a key ally to help it gain entry to the Nuclear Suppliers Group -- a group of nuclear supplier countries that regulate nuclear-related exports in order to prevent nuclear proliferation. Italy and China have opposed India's membership, saying it - like other members - must first ratify the nuclear non-proliferation treaty.

China's Foreign Ministry spokesman Lu Kang said in May: quote: "We have talked about our position many times. The NSG is an important part of the international nuclear non-proliferation regime which is based on the cornerstone of the Treaty on the Non-Proliferation of Nuclear Weapons (NPT)."

India's ambassador to the United States also told reporters last week - Westinghouse and India are in advanced stages of the negotiating a deal to build six nuclear power plants in India. 

The talks have hinged on New Delhi and Washington developing a new workaround to India's civilian nuclear liability law considered a sizeable hurdle for the country's nuclear-suitors.

"What we have come up with is an insurance product. Primarily led by India government owned insurance companies to out money in a pool. That suppliers can buy into that would absolve them or at least pay off claims that arise from some type of nuclear accident in the future. 2:43 We are all waiting to see whether Westinghouse and other suppliers look at this insurance product as good enough for them to make the bet at becoming suppliers for India," said Rick Rossow.

On Wednesday, Prime Minister Modi will make a first-time address to the US Congress. It is the same body which passed law that prevented him into this country back to 2005, for reasons related to India's violent religious conflicts. Modi remains the only person ever denied entry to the United States on those grounds.