Observing that India was projected to become the world's third largest economy by 2015, the United States has said it wants New Delhi to be a strong trading and economic partner.

"India is projected to become the world's third largest economy by 2015, and we want it to be a strong trading and economic partner," US Assistant Secretary of State Christina Rocca said addressing academics at the Center for Advanced Study of India at the University of Pennsylvania.

Rocca said the US-India relationship was maturing rapidly and was probably better than it ever was since 1947.

"The two countries' leaders meet often and speak with each other even more often. Our military ties are growing as well, with army, air force and naval exercises steadily expanding in frequency and scope," she said on Wednesday.

Maintaining that trade between US and India, despite being largest trading partners, remained 'far below what it could be,' Rocca stressed on expanding the commercial relationship.

She said the US Ambassador to India David Mulford was a financier by profession who was working hard to overcome more quickly the barriers that stand in way of a significantly bigger, freer and more productive relationship.

Politicians had realised that the world's two largest democracies have had more that ties us together than pulls us apart, Rocca said.

She said President George W Bush and Prime Minister Atal Bihari Vajpayee had announced steps to implement their shared vision for rapid transformation of relationship between the two countries.