The US sees India as a key Asian ally and trading partner
US President George W Bush is shortly due to begin talks in Delhi on his first visit to India, which could see a nuclear power deal clinched.
"It's an honour to be here. I've never been to India before," he said in brief comments after being ceremonially welcomed at the presidential palace.
His arrival on Wednesday prompted an anti-war rally in Delhi attended by about 100,000 people, mainly Muslims.
But he will be welcomed by many other Indians, a BBC correspondent notes.
Mr Bush inspected a ceremonial guard of honour at the imposing colonial-era presidential palace in the heart of Delhi.
He is following that by a wreath-laying at Raj Ghat, the memorial to Mahatma Gandhi before his talks with Indian Prime Minister Manmohan Singh at Hyderabad House.
“ Our relationship with India is broader than our discussions about energy - ours is a strategic relationship ”
George W Bush
Both leaders hope they can finalise a deal to provide India with civilian nuclear technology in return for Delhi opening some of its nuclear facilities to international inspection.
Greater economic links will also be discussed and delegations of Indian and US business leaders will meet.
The BBC's Jonathan Beale who is travelling with President Bush says the visit shows a growing bond between the two countries' leaders.
Angry protests
The streets surrounding Mr Bush's hotel have been sealed off and hundreds of policemen and US secret service agents are in position around it.
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US-India 'seismic shift'
The BBC's Sanjeev Srivastava notes that many protests are planned against the US leader, who arrived from Afghanistan where thousands of American troops are still active in the "war against terror".
Those who turned out in Delhi on Wednesday held up black flags and placards reading "Bush, go home".
"We are against Bush because he is the enemy of Islam," one protester, Shamsuddin Malik, told the BBC.
India's Muslim minority is one of the biggest Islamic communities in the world.
In Calcutta, tens of thousands of supporters of left-wing parties marched through the city centre to call on India not to become a "US lackey".
Nuclear deal
The nuclear deal was agreed to in principle during a visit by the Indian prime minister to Washington last year.
But it has been held up by differences over plans to separate India's civilian and military nuclear programmes and open its civilian nuclear facilities to international inspectors.
Speaking to reporters in Afghanistan, Mr Bush stressed that partnership with India was more important than any one deal.
"Our relationship with India is broader than our discussions about energy - ours is a strategic relationship," he said.
During his trip, he will also visit the southern city of Hyderabad, one of India's high-technology hubs.
After India, he will head to Pakistan where President Pervez Musharraf says he hopes the US leader will be able to play a role in resolving the long-running Kashmir dispute with India.
