Indian Prime Minister Manmohan Singh arrived at the White House on Friday for talks expected to focus on regional security and implementing a key nuclear deal with the United States.

Singh was making what may be a farewell visit to President Barack Obama's Oval Office, as he is seen as unlikely to run for a third term in next year's election.

The two leaders, who have forged a close personal relationship, were to hold talks before making statements to the press.

Singh -- increasingly battered by corruption scandals, a slowing of India's economic growth and a weakening rupee -- will be keen to stress a warming of relations with Washington as a highlight of his decade in office.

Obama has seen improving ties with New Delhi as a centerpiece of his strategy of shifting US economic and diplomatic resources to Asia, and views India's vibrant democracy as a kindred national spirit to the United States in a region where political freedoms can be fleeting.

Obama hosted Singh for the first state dinner of his presidency in 2009 and paid his own state visit to India a year later. Vice President Joe Biden was in India in June and a long string of US cabinet-level officials have trekked to the country.

There are expectations of progress on a dispute over liability payments that US nuclear firms would face in the event of a disaster involving equipment they install in Indian power stations.

Obama and Singh also meet at a high point of US-India defense cooperation. New Delhi has bought nearly $9 billion in US defense articles since 2008, officials say and both sides want to do more business.

India is meanwhile alarmed that visa reforms in a proposed US immigration bill in Congress could disproportionately punish its thriving information technology and software sectors.