NEW DELHI (AFP/AP) - US Vice-President Joe Biden arrived in India on Monday at the start of a four-day visit designed to revive momentum in flagging diplomatic ties and fire up bilateral trade.

Mr Biden, the first US vice-president to visit India in three decades, landed in New Delhi shortly after 5pm or 730 pm Singapore time. He visited New Delhi in 2008 as a senator.

Mr Biden will meet senior leaders including Prime Minister Manmohan Singh in New Delhi before heading to financial hub Mumbai to deliver a keynote speech on the economy.

In an interview published in Monday's Times of India newspaper, Mr Biden said the world's two biggest democracies had a "tremendous capability to work together" and should be doing more.

His trip is viewed as a major step in promoting President Barack Obama's focus on forging strong partnerships in the Asia-Pacific region aimed at counterbalancing China's power.

India and the United States will also discuss regional security, including efforts to end the conflict in Afghanistan.

The US increasingly views India as a partner in developing Afghanistan, where New Delhi has provided US$2 billion (S$2.5 billion) in assistance. Washington also wants India to play a more active role in training Afghan security forces as the US and its NATO allies withdraw combat forces by 2014.

During the Cold War, relations between India and the US were strained as America tilted towards India's arch-enemy Pakistan and India turned towards the Soviet Union. Relations have thawed since then, with New Delhi and Washington signing a defence cooperation pact in 2005 and ratifying a landmark civil nuclear agreement in 2008.

More recently, the Obama administration has reaffirmed India's role in its Asia-Pacific policy.

"Our goal is to help tie Asia-Pacific nations together - from India to the Americas - through strong alliances, institutions and partnerships," Mr Biden said in Washington last week.

However, Indian analysts said New Delhi would have its own questions over the new policy.

"When President Obama came up with his pivot to Asia policy, it was widely welcomed in India. Because the pivot was seen as an effort to create a balance against very aggressive Chinese policies," said Mr Lalit Mansingh, a former Indian ambassador to the US.

"Then the Americans moderated it by calling it a rebalance. And they have further diluted it by saying it is not meant against China," he said.

"India would have liked a more vigorous stand on China where its security interests will be protected. So, this will be one of the issues India would like to discuss," Mr Mansingh said.

Mr Biden and Indian leaders were also expected to discuss hurdles to trade and restrictions on American companies doing business in the Indian marketplace.

In a speech in Washington on Thursday, Mr Biden noted that trade between the countries had increased five-fold over the past 13 years, but there was no reason it should not expand five times as much again.

Despite the increasing trade, US business groups have complained about the slow pace of economic reform in India and have urged New Delhi to open up its markets further.

The Indian government in recent months has loosened rules governing foreign investment in some areas of the economy.

American businesses have been pressuring the Obama administration to press India for stronger intellectual property protection.

New Delhi is expected to raise concerns about proposals in the US Congress that would curb visas for high-tech Indian workers.

Mr Biden will be accompanied during the visit by his wife, Jill, who will visit a US supported public health programme in Agra and then tour the nearby Taj Mahal.

The Bidens will then head to Mumbai before leaving for Singapore on Thursday.