US President Barack Obama on board the Air Force One.
Describing the unprecedented second visit of US President Barack Obama to India as "game changing" the White House has said the Obama-Modi meeting would "elevate the nature of the relationship" between the two largest democracies of the world.
"This opportunity that the President has to go and attend (the Republic Day Parade) as the Chief Guest, really offers the opportunity to elevate the nature of our relationship," Phil Reiner, Senior Director, National Security Council for South Asia at the White House, told PTI in an interview on the eve of Mr Obama's departure for India.
"In my personal opinion, this is a seminal moment and potentially a game changing opportunity for the relationship. This is a relationship in which the President has invested a great deal of time, trying to elevate the nature of our partnership," said Mr Reiner, who is the point person for India and South Asia in the National Security Council.
Responding to questions, the senior White House official said during the three-day visit progress could be seen in key areas of defence and security, clean energy and climate change and nuclear co-operation.
These are all pieces of strategic co-operation that the US not only has an interest in continuing forward, but had really heightened level of ability to engage since September, he added.
After President Obama accepted Prime Minister Narendra Modi's invitation to be the chief guest at the Republic Day, the message from the top was to seize the opportunity in not just a symbolic way but also in terms of substance, he said.
"The very clear message internally here was accepting that symbolic gesture, accepting this huge opportunity was also to use this moment to make it substantive. The message from the very beginning was let's seize this opportunity not only in a symbolic way but also in terms of substantive way," he said.
After the September 30 Obama-Modi meeting there has been reinvigoration of the two bureaucracies, driving things at a very senior level in order to clear out the underbrush and move forward with those elements of strategic partnership.
"Going forward, we have a very robust agenda," Mr Reiner said, adding everything they are working on is very much facilitated by the fact that there is a very nice relationship between the two leaders.
This visit only offers to increase that opportunity, he said, adding that these could be in areas like space cooperation, cancer research or intellectual property. So there is an increase in momentum to the relationship by the leadership-level engagement, he said.
"It offers the opportunity to drive both bureaucracies forward, which on the whole really creates an elevated partnership," Mr Reiner said.
"We look forward to a robust bilateral agenda in the defence space," he said when asked about the possibility of signing of a renewed defence partnership agreement.
Mr Reiner said both the President and First Lady Michelle Obama are excited about getting back to India.
They both look back at their original visit in November 2010 and have great memories from that trip.
President Obama, he said, has been "very much attentive" to elevate the nature of relationship.
The fact that it is for the first time that a US President has been invited as the Chief Guest, is a "tremendously symbolic gesture" by Prime Minister Modi and there is a huge message sent by that gesture, he said.
Referring to the series of meetings the two countries had between PM Modi's US visit in September and before the trip, he said this is really one of the most intense periods of the relationship.
"All these have been incredibly important for not only US national interest but also for the Prime Minister and the people of India. It has been an intense period. It has been a productive period," he said.
Referring to reports about Barack Obama's security in the Indian media, Mr Reiner said there has been a lot of speculation.
"This is not something that is uncommon. Whenever the President of the United States travels to any other part of the world there is need for heightened security. I think the stories would indicate that there is an unusual level of concern. My understanding is that is not necessarily the case in terms of how we see things," he said to a question.
While Phil Reiner would not comment on the type of gifts that the President is taking for Modi and other Indian dignitaries, he said the biggest gift from the prime minister to the people of the United States is the invitation to Obama to attend the Republic Day Parade as chief guest.
"The real gift here was the invitation from the Prime Minister of India to the President of the United States. The President has accepted that and he looks forward to engaging with people of India directly when he is in the country," he said.
"It is an incredible opportunity for both nations," he said.