India and France on Saturday signed a key security accord for the Indian Ocean to counter China's growing influence in the region as visiting French President Emmanuel Macron said defence ties between the two nations had reached a new high.
"Defence co-operation between the two countries now has a new significance," Mr Macron in New Delhi as Indian Prime Minister Narendra Modi stood by his side.
Under the deal, India and France will open their naval bases to each other's warships, a move seen as an attempt to check China's territorial ambitions.
"A strong part of our security and the world's stability is at stake in the Indian Ocean," Mr Macron said.
"The Indian Ocean, like the Pacific Ocean, cannot become a place of hegemony," he said.
Mr Modi said the accord was crucial as the Indian Ocean region would play a "very significant role" in future.
China's territorial ambitions in the South China Sea already worry world powers. And its move into the vast Indian Ocean – stretching from the Suez Canal to the Malacca Strait – has heightened that concern.
Mr Modi and Mr Macron are particularly anxious as China extended its military presence by opening a naval base in the eastern African nation of Djibouti last year.
Beijing is also building up a trading network – the so-called One Belt One Road initiative - which involves many of the Asian and African nations that line the Indian Ocean.
It has built a port in Pakistan's Gwadar, taken a 99-year-lease on Sri Lanka's Hambantota and bought a number of tiny islands in the Maldives.
All of this has alarmed India, which sits at the heart of the Indian Ocean region.
The comments from Indian and French leaders followed a slew of agreements signed by the two countries in the spheres of defence, space and clean energy on Saturday.
"From the ground to the sky, there is no subject on which India and France are not working together," Mr Modi said.
A technical agreement was also signed on the French-assisted nuclear power project at Jaitapur in western Maharashtra state.
Sources in the French presidency said they were optimistic of a final agreement being signed before the end of the year.
The $9.3 billion (Dh34bn) framework agreement for six nuclear reactors was signed during a visit to India in 2010 by then president Nicolas Sarkozy.
But the project has since run into stiff opposition from environmentalists concerned about seismic activity in the area and fears about the safety of nuclear power in the wake of the Fukushima nuclear disaster in Japan.
Earlier in the day, Mr Macron spoke about his personal rapport with Mr Modi which was established after their meeting in Paris last year.
"I think we have very good chemistry, our two great democracies have a historic relationship," the French president said.
Mr Modi broke protocol to receive Mr Macron at the airport, exchanging warm hugs and robust handshakes.
"You welcomed me in Paris last year with an open heart and a lot of warmth. I am happy that I have got an opportunity to welcome you in India," Mr Modi said at the start of his speech on Saturday.
On Sunday, Macron will attend a solar power summit designed to showcase India and France's commitment to fighting climate change, which both leaders have made a priority.
Travelling with his wife Brigitte, the French president will also visit the monument to love, the Taj Mahal, a few hours drive from the Indian capital on Sunday.
On Monday, he heads to the Hindu holy city of Varanasi on the banks of the river Ganges, which the Indian premier has promised to modernise and clean up.
Mr Macron's visit comes after a somewhat misstep-laden visit to India by Canadian Prime Minister Justin Trudeau.
Both he and Mr Macron are often compared internationally because of their broadly similar political views, as well as youth and good looks.
But Mr Trudeau's visit hit a series of embarrassing bumps and he received a fairly cool reception during his stay in India.
He was pilloried on social media and in the Canadian press for donning traditional Indian clothing at every opportunity.
And there were red faces when it emerged that a former Sikh militant was invited to a dinner with him in Mumbai.
Mr Macron has so far opted for more sober and predictable dress – a dark suit.