The United States and India have pledged to deepen their defense ties after so-called "2 plus 2" talks in Washington on Wednesday. India's Foreign Minister, Dr. Subrahmanyam Jaishankar, and Defense Minister, Rajnath Singh, met their counterparts at the U.S. State Department.

The talks covered everything from defense, Afghanistan, trade and cooperation in space, all signs of the growing strategic partnership between the U.S. and India.

Mark Esper, the U.S. secretary of defense, said increased U.S. arms sales to India are a cornerstone of the relationship.

"It's not just about equipment and hardware or software. What it does is it gets to the improved interoperability between our two militaries, better understanding of how to fight better together if called upon to do, so I think it's much broader than that," said Esper.

Two of the Indian government's top ministers were in Washington as protests rage across their country over a new citizenship law. India's foreign minister insisted the law, which offers citizenship to non-Muslims from three neighboring countries, isn't discriminatory.

"If you look at what those countries are, and therefore what their minorities are, perhaps you'd understand why certain religions were identified," Jaishankar told a reporter at a press conference following the talks.

Overall, the four ministers tried to maintain a united front during this visit. However, India is still moving forward with a deal to buy the S-400 missile system from Russia and that's causing a lot of concern in Washington.