AHMEDABAD: The United States ended a decade-long boycott Thursday of Indian opposition leader Narendra Modi over deadly religious riots as a top diplomat held talks with the man tipped to be the next prime minister.

Nancy Powell, the US ambassador to India, shook hands with Modi at his official residence in the western state of Gujarat where he is the chief minister, before entering closed-door talks.

Powell and her entourage arrived in four official cars at the residence in the state capital Gandhinagar, but she did not speak to waiting reporters.

Modi, leader of the Hindu nationalist Bharatiya Janata Party (BJP), is accused by rights groups of turning a blind eye to riots that killed up to 2,000 people in Gujarat in 2002.

Most of the victims were Muslims.

The United States in 2005 revoked a visa for Modi under a domestic law that bars entry by any foreign official seen as responsible for “severe violations of religious freedom”.

Modi has denied any wrongdoing over the 2002 violence and investigations have cleared him of personal blame, although one of his former ministers was jailed for life for instigating the killing of 97 Muslims.

Powell's meeting with Modi puts the US in line with European nations and Australia, which have already restored ties with him.

Opinion polls show Modi and his party are on course to topple the ruling Congress party at general elections expected in May.

'Business savvy' leader

Modi, 63, is the prime ministerial candidate of the main opposition Bharatiya Janata Party (BJP), which is ahead of the incumbent Congress party in opinion polls.

He has sought to portray himself as a business-savvy leader who can champion India's economy and tackle corruption after a decade of rule by the left-leaning Congress party.

Neelam Deo, a former diplomat and foreign policy expert, said the US overture to Modi reflected the “assessment... that the BJP candidate has a good chance of coming ahead in the elections”.

Foreign ambassadors are also engaging with Modi because “of their own companies seeking business opportunities in Gujarat, which has certainly grown more rapidly than many of the other state in India”, she said.

The United States and India have built a growing relationship since their estrangement in the Cold War, with most US lawmakers supportive of ties with New Delhi.

But Modi has faced opposition from an unlikely mix of left-leaning members of the US Congress active on human rights and other conservative politicians.

A congressional aide has said a meeting with Powell would send a signal of US openness on issuing a visa.

But some US officials are believed to be worried that bitterness over the past visa rejection would cloud relations with Modi if he becomes prime minister.

Concerns over personal treatment are hardly new to the US-India relationship.

In December, the two countries went through one of their worst crises in years when US authorities arrested a New York-based Indian diplomat on charges of underpaying her servant and lying on the worker's visa form.

Indian lawmakers and commentators accused US authorities of humiliating the diplomat through a strip-search.

The row abated a month ago when the diplomat, Devyani Khobragade, was allowed to return to India just as she was indicted.

Both governments have since voiced hope at moving forward. But the United States earlier Monday renewed one rift when it announced it would take India to the World Trade Organisation in hopes of opening up its booming solar power industry.