NEW DELHI: Barack Obama arrives in India this weekend for an unprecedented second visit by a serving US president, the honoured guest of his new friend Narendra Modi who was a Washington outcast only a year ago.

As well as holding bilateral talks, the leaders of the world's two largest democracies will address CEOs, appear on a radio phone-in and watch a spectacular parade together in a visit that underscores their closeness.

Security is increased at the Taj Mahal in preparation for the visit of US President Barack Obama, in Agra on January 21, 2015. — AFP

The US president and wife Michelle will also travel to the Taj Mahal, with hundreds of photographers on hand to snap the first couple's visit to the ultimate monument to love.

Obama's courtship of Prime Minister Modi is evident from his three-day itinerary, the first time an incumbent president has returned to India.

While recent swings through Asia have included multiple stopovers, India is Obama's only destination this time, despite the risk of offending neighbouring Pakistan.

“There's no question this is a defining time in the US-India relationship, “US Ambassador Richard Verma said in New Delhi Wednesday. “Things not only feel different, they are different."

Modi's election in May 2014 was a potential headache for the US, which had blacklisted the Hindu nationalist for more than a decade after deadly communal riots in Gujarat when he was state chief minister.

He was only brought in from the cold last February when Verma's predecessor travelled to Gujarat once it appeared Modi was likely to end the centre-left Congress party's 10-year rule.

The transformation since has been spectacular, with both men heartened by their meeting of minds on a range of issues in Washington in September.

The US website Politico described their summit as a “love-in” and predicted Modi could become “America's new best buddy”.

Twitter invite

Modi's November invitation “to have a friend over” was issued via Twitter and Obama's quick-fire acceptance underlined a sense of coordination.

One cloud was lifted in November when the two governments resolved a row over food subsidies that had been blocking a global trade agreement.

Obama's top diplomat, Secretary of State John Kerry, even called Modi a “visionary” on an advance visit last week.

Obama will be the main VIP at Monday's Republic Day parade when India's military showcases everything from tanks to its camels.

“For President Obama to be invited as the first US president to attend as the chief guest sends a very important message to the world,” US Deputy National Security Advisor Ben Rhodes told reporters in Washington.

“There is extraordinary potential in this relationship... Our goal is to lead this relationship in a fundamentally different place than it was when President Obama took office and when Prime Minister Modi took office.

“We believe we have a unique moment of opportunity to have that type of breakthrough."

Observers are not expecting major policy announcements, although a deal on intelligence sharing is on the cards and decade-old defence cooperation pact is expected to be upgraded.

“I think strengthening our ties with US, with the already existing framework enhancing its scope, is definitely beneficial to the country, “Defence Minister Manohar Parikar told Indian television.

Speaking at a conference organised by the Brookings India think-tank, former foreign secretary Kanwal Sibal said there were unlikely to be other big breakthroughs in Sunday's talks as “we have not given ourselves enough time since September."

Climate change and Afghanistan are expected issues on the agenda, while particular focus will be on the economy after Modi pledged to make India “the easiest place” to do business.

Courting business

Obama and Modi will make a joint address to company bosses on Monday in an event organised by the US-India Business Council.

“With business sentiment at an all-time high, the timing could not be better,” said the organisation's acting head Diane Farrell.

US Ambassador Verma said bilateral trade was now running at around 100 billion dollars a year — five times the level of a decade ago — and saw no reason it couldn't grow by another five times.

Officials in Washington have admitted a certain degree of surprise over the upswing in ties.

The rapid escalation of a row over the strip-search of an Indian diplomat in New York in late 2013 — which saw the Stars and Stripes torched on the streets of Delhi — hinted at a latent anti-American sentiment in a country that still sees Russia as its most reliable ally.

But both sides share a common goal in wanting a counter-balance to China, even if President Xi Jinping beat Obama to a Modi invite.

Modi did not eat with Obama in Washington as he was observing a religious fast.

But reports say Modi will host his first private dinner for Obama at his Delhi home and has asked about the dream menu of the president — who once learnt how to cook the Indian staples of daal and keema.