US President Barack Obama is due to hold talks with Indian Prime Minister Manmohan Singh and address the Indian parliament on the third day of his visit to India.
Mr Obama arrived in the capital Delhi on Sunday afternoon, from Mumbai where he announced $10bn (£6.2bn) in new trade deals with India.
He also criticised the pace of Pakistan's fight against militants within its borders.
The US president on a 10-day Asian tour designed to boost US exports.
After a ceremonial welcome at the Indian president's palace, Mr Obama said India is "already a world power". He also laid a wreath at a memorial to Indian independence leader Mahatma Gandhi.
Mr Obama said during his talks with the prime minister, president and other Indian leaders that he would aim to strengthen co-operation between the two countries and discuss issues like "counter-terrorism and people to people contact".
Mr Obama is also expected to meet Congress party president Sonia Gandhi and opposition leader Sushma Swaraj.
Speaking with a group of students in Mumbai on Sunday, Mr Obama called for dialogue between India and Pakistan, adding that India was the country with the biggest stake in Pakistan's success.
Mr Obama is expected to elaborate on his vision for US relations with India in his address to the Indian parliament.
US support for Pakistan is one of the most sensitive issues Mr Obama faces during his visit, says the BBC's Mark Dummett in Delhi.
Many Indians think the US cannot be trusted as long as it continues to supply weapons to Pakistan's army, this country's "enemy number one", our correspondent adds.
In Mumbai, Mr Obama visited the scene of the 2008 attacks, saying India and the US were united against terrorism.
Trade between India and the US was worth about $40bn in 2008 - still significantly less than US trade with other partners like China and Europe.
Security is tight for Mr Obama's visit. Thousands of Indian and US security personnel are deployed and a US naval warship is on patrol in the waters off the coast of the city.
Later on his trip, Mr Obama will announce a "comprehensive partnership" including economic ties in Indonesia, attend a G20 summit of global economic powers in Seoul and participate in an Asia-Pacific economic forum in Yokohama, Japan.