The US says, India has an important role to play in responsible stewardship of nuclear weapons and materials. During his meeting with National Security Advisor Ajit Doval ahead of Prime Minister Narendra Modi's Washington visit, US Secretary of State John Kerry said India is the largest democracy in the world, and a real partner with the United States on a lot of technology and energy issues. <br/><br/>He said, US is particularly grateful to India for the leadership it offered in Paris helping to reach a climate agreement. And now, there is more that we can do with respect to the next steps in that agreement, Kerry added. <br/><br/>US Secretary of State said President Obama has called the relationship with India a defining relationship of this century, and there are many reasons for that. <br/><br/>He hoped that this Nuclear Security Summit will contribute to everybody's understanding about our global responsibilities and choices. <br/>Mr.Doval said India was deeply interested in ensuring safety and security of radioactive materials. Hoping for increased cooperation with the US, Mr Doval said both the countries would look to work together on their shared concerns, including terrorism and cyber space.