The two leaders chatted, mostly without the help of an interpreter, who was seated within the bullet proof enclosure. Within the enclosure was also President Pranab Mukherjee, US president's wife Michelle Obama, Vice President Hamid Ansari and his wife Salma.

Modi, whose sartorial vibrancy was also remarked on by Obama, was attired in a dark bandhgala and topped with a colourful tricolour Rajasthani turban. Modi is known to pay special attention to his attire and has become known for changing his dress for different occasions.

On Sunday, during the presidential banquet, Obama had complimented Modi's dressing style and said "Tonight I was thinking about wearing a Modi kurta myself" - a reference to the popularity that Modi has brought to the kurta, matched with differently coloured sleeveless jackets.

While Obama was wearing a formal dark grey suit, with a lavender coloured tie, Modi topped his attire by donning a pair of stylish shades.

Michelle was seen chatting with Salma Ansari, but mostly kept quiet and watched the proceedings.

In the initial moments of the parade, when the tanks, missiles and armoured cars were wheeled on Rajpath, Obama looked on with interest, and continued to look interested in the long march past by different wings of India's armed forces.

Towards the end of the march past, when the mounted floats from different states and the folk dancers came in a steady stream to showcase their cultural splendour, the attention of the US president appeared to flag.

But his companion, in Modi, kept up a lively chatter - explaining each bit with an expressive show of his hands.

Ironically, many of the showpieces exhibited at the parade are of Russian vintage - an indication of India's reliance on an old ally for its important weaponry and armaments.

Among the exhibits were the BrahMos, the world's fastest short range ramjet supersonic cruise missile, jointly developed by India and Russia. The T-90 Tank, Bhishma, was also exhibited. It is originally a Russian third-generation main battle tank and a mainstay of the military. The Sukhoi Su-30MKI fighters from Russia swooped down on the sky towards the finale.

Obama did get to see some of the US-made acquisitions of India - the Indian Air Force's C-130J Super Hercules and C-17 Globemaster III - that flew down at low level formation over the Rajpath.

The daredevil motorbike stunts by men of the Border Security Force had the US president and his wife visibly interested and both clapped with enthusiasm.

On Sunday, Modi and Obama had taken a stroll in the lawns of Hyderabad House and chatted over tea -- in informal talks without aides, in what was called a "Chai pe Charcha" moment.

The talks Sunday also saw the two sides announce clinching of the agreement for implementation of the civil nuclear agreement, a major highpoint in India-US ties and the elevation of the bilateral relationship with a new India-US Delhi Declaration of Friendship.

The successful holding of the Republic Day parade, which marks perhaps the longest period of time that the US president has spent in the open in any country, went off without a hitch -- marking a high point for the security detail put in place for the VVIP guest who has the highest level of security in the world.

Modi's invite to Obama to be chief guest, and the latter's acceptance of the invite, has been described as a major triumph in diplomacy by the Modi government that has taken major strides in foreign policy since it came to power seven months ago.

Obama did come in his own car, The Beast, to the Rajpath, in a break from protocol and not in President Mukherjee's black limo.