WASHINGTON (AFP) - The US ambassador to India plans to meet opposition candidate for prime minister Narendra Modi, an official said on Monday, signalling a turnaround after years of shunning him over anti-Muslim riots.

Ambassador Nancy Powell's meeting with the Hindu nationalist leader would put the United States in line with European nations which have already ended a boycott of Modi amid growing indications that he will take the helm of the world's largest democracy later this year.

A State Department official confirmed the appointment between Modi and Powell, without specifying a date.

"This is part of our concentrated outreach to senior political and business leaders which began in November to highlight the US-India relationship," the official said on condition of anonymity.

Human rights groups say that Modi, the chief minister of the western state of Gujarat, turned a blind eye to riots in 2002 that killed up to 2,000 people, most of them Muslims.

The United States, under domestic laws related to human rights, in 2005 revoked Modi's visa saying he was "responsible for the (lack of) performance of state institutions" during the riots.

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

The United States and India have had a growing relationship since 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 conservatives concerned over the status of evangelical Christians.

A congressional aide said that a meeting with Powell would send a signal of US openness on issuing a visa - an issue on which the United States has little way of changing course unless Modi again applies to travel to the United States.

"A meeting with the ambassador could be a way of signalling, 'You'll get a visa,' without having to say it, which she can't," the aide said on condition of anonymity.

Modi 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.