NEW DELHI - Barack Obama will become the first US president to be chief guest at India's Republic Day parade on Monday, a day after hailing a new era of friendship between the world's biggest democracies.
The invitation to the annual celebration of the birth of modern India is one of the biggest honours the country can bestow on a foreign leader and underscores the growing closeness between Obama and India's Prime Minister Narendra Modi.
Security will be tight for the parade, a colourful display of India's military might and cultural diversity showcasing everything from tanks and state-of-the-art weaponry to camels and traditional dancers.
The parade celebrates the adoption in 1950 of the Indian Constitution - the day that India became a republic - three years after gaining independence from Britain.
Modi, who issued the invitation via Twitter saying he hoped to "have a friend over", will watch the parade with Obama from behind a bulletproof glass enclosure.
The area has been declared a no-fly zone and snipers will be positioned on rooftops along the route, where 15,000 new CCTV cameras have been installed.
The show-stopper is the Border Security Force on their brightly-decorated camels, and the parade also includes carnival-style floats and a human pyramid atop moving motorbikes.
Obama's presence as chief guest represents a remarkable turnaround in his relationship with India's new leader, who only a year ago was persona non grata in Washington.
He began his visit on Sunday with a bear hug from Modi, later saying their new "friendship" reflected a natural affinity between the two countries, which are both seeking a counter-balance to a rising China.
"I'm honoured to be the first American president to attend this celebration, as well as the first president to visit India twice," said Obama.
The US president's second visit to India since taking office has seen no major policy announcements, apart from a breakthrough on a long-stalled nuclear pact.
Environmental campaigners expressed disappointment that India made no substantive announcements on emissions after the talks.
India has stuck to its guns even though China and the US unveiled emissions pledges, and is seen as one of the main obstacles to a global climate change deal due to be signed in Paris in December.
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 the then US ambassador Nancy Powell travelled to Gujarat once it appeared Modi was likely to end the centre-left Congress party's 10-year rule.
Since coming to power, Modi has borne no obvious grudge. He has invited Obama to co-host a radio phone-in show and is reportedly planning a private dinner for the president at his Delhi home.
The two leaders will on Monday make a joint address to company bosses in an event organised by the US-India Business Council.
Modi is seeking to attract global business to manufacture in India to fulfil his election pledged of creating enough jobs for the burgeoning young population.
US Ambassador Richard Verma said before Obama's arrival that trade was now running at around US$100 billion (S$134.5 billion) a year - five times the level of a decade ago - and saw no reason it couldn't grow by another five times.
Obama had been scheduled to visit the Taj Mahal with First Lady Michelle Obama, but his trip has been cut short to allow him to travel on to Saudi Arabia and pay respects to new King Salman.