India initiated its request to buy 22 Guardian MQ-9B unmanned aircraft for maritime surveillance last year. The deal is estimated to be worth about $2 billion. The transaction is still subject to congressional approval.
Since 2008, India has signed U.S. defense contracts for things like C-130J and C-17 transport aircraft, P-81 maritime patrol aircraft, Harpoon missiles, and Apache and Chinook helicopters.
Defense spending isn't the only topic presumably at the table between the two leaders. Immigration and the hotly contested H-1B program may also be discussed.
The prime minister also spent time with U.S. CEOs during his visit, meeting with high-profile leaders on Sunday and earning rave reviews.
Apple CEO Tim Cook and Amazon CEO Jeff Bezos were among those in attendance. When CNBC asked Cook how the meeting went, he responded by saying "fantastic."
Rick Rossow, senior advisor at the Center for Strategic and International Studies, told CNBC the corporate relationships may somewhat overshadow the one between the two governments.
The two countries "haven't been able to find common ground," he said in an interview with "Closing Bell."
"But CEOs are still investing. India's the largest destination for foreign investment in the world this year. It's becoming one of America's largest trading partners," he added.
Companies that would benefit from a growing trade relationship with India would be ones that the Indian or its key state governments have highlighted, said Rossow.
"Right now they have really liberalized the oil and gas sector, they've liberalized coal production. They're also undertaking a massive renovation of the broke electric power grid. So if you're a company that sells electric power equipment or related services, you've got a great opportunity out there," he said.
— CNBC's Seema Mody and The Associated Press contributed to this report.