US Vice-President Joe Biden held talks with Indian leaders on Tuesday as he sought to calm fears over the exit of US troops from Afghanistan and capitalize on growing investment opportunities.

Biden met his counterpart Hamid Ansari at the start of a round of talks that will include sessions with Prime Minister Manmohan Singh, President Pranab Mukherjee and a top opposition figure.

The vice-president, the most senior US official to visit India since President Barack Obama in 2010, has said the two countries share common goals on a range of regional security issues.

But there is widespread unease among Indian leaders over what will happen in Afghanistan once US troops have left in 2014, with many fearing that Pakistan has most to gain from the withdrawal.

India has spent more than $2 billion in aid in Afghanistan since the Taliban were toppled in the 2001 US-led invasion.

In an interview ahead of his arrival, Biden said the Taliban had a part to play in the political process as long as they renounced violence.

"Our goal is for Afghans to be talking to Afghans about how they can move forward, end the violence and start rebuilding their country," he told The Times of India.

"We have been clear that if the Taliban are to have any role in Afghanistan's political future, they will need to break ties with al-Qaida, stop supporting violence and accept the Afghan constitution as part of the outcomes of any negotiated peace settlement."

Indian and US officials have pointed to Biden's visit as a chance to heat up the investment climate and crank up the levels of bilateral trade, which are on course to reach around $100 billion a year.

But in a sign of the frustration among US investors over the obstacles they face in doing business in India, a Washington-based lobby wrote an open letter to Biden urging him to address what it called "India's unfair trade and intellectual property practices".

Biden "has a unique opportunity to show the administration's commitment to protecting US innovative and creative sectors by raising this important issue during his high-level meetings in India", Mark Elliot, a co-chair of the Alliance for Fair Trade with India, wrote in the letter.

The issue of intellectual property has been a major bone of contention in trade ties for years, with the US pharmaceutical industry consistently accusing India's huge generics industry of riding roughshod over patents.

Agence France-Presse