Amit Shah has been re-elected president of India's ruling Bharatiya Janata Party (BJP) for the next three years.

Shah, 51, a close confidante of Prime Minister Narendra Modi, was elected unchallenged in a process widely seen as a formality, reports our New Delhi correspondent.

"There was no other nomination because there was a consensus in the party," senior BJP leader and Shah's immediate predecessor in the top party post Rajnath Singh told reporters.

Prime Minister Narendra Modi, Rajnath Singh and several BJP chief ministers proposed Shah's name.

This is Shah's first full term as the party head. He took charge as BJP chief in July 2014, midway during the tenure of Rajnath Singh as BJP president after the latter joined the government as home minister.

The election of Shah as party chief reasserts Modi's grip over BJP and there was consensus in both the party and RSS that Shah should get a full term as party head.

During Shah's previous term, BJP came to power in Maharashtra, Haryana, Jharkhand and Jammu and Kashmir states but quite a bit of that sheen was rubbed off by the party's defeats in the Delhi and Bihar state legislature polls.

In the coming years, BJP under Shah will get ready for legislative assembly polls this year in states like Assam, West Bengal in the east and Kerala in the south where the party has never been a major political player.

Shah is also set to lead Modi's 2019 national campaign and also the mega battle for power in India's most populous state of Uttar Pradesh in 2017. In the 2014 national election, BJP won 72 of the state's 80 parliamentary seats but has lost ground ever since in local body elections and by-polls.