By Sanjoy Majumder
BBC News, Delhi
Japanese Prime Minister Shinzo Abe has arrived in Delhi on his first ever visit to India.
Mr Abe will focus on trade
Mr Abe is due to hold talks with his Indian counterpart, Manmohan Singh, and will sign a series of major agreements, mainly aimed at doubling trade.
The two leaders are also expected to hold talks on civilian nuclear and defence deals.
Analysts say India and Japan foster a strategic relationship which many believe is aimed at countering China.
Mr Abe arrives at the head of a major business delegation, including chief executives of Japanese companies such as Toyota, Mitsubishi, Canon and Hitachi.
Trade is the main focus of the visit - it stands at nearly $7bn at present but a study by India's main Chambers of Commerce suggests it can be doubled in five years.
Both governments will announce a plan to jointly develop an ambitious manufacturing and freight corridor between Delhi and the financial capital, Mumbai.
It will include a high-speed railway line, several ports and airports, rather like that between Tokyo and Osaka.
But perhaps the most significant aspect of the visit is in building a strategic partnership.
Japan was severely critical of India's nuclear tests in 1998 and suspended economic ties in its wake, but now it is willing to discuss co-operating in the field of civilian nuclear technology and even defence.
Mr Abe favours an alliance between Japan, Australia, the United States and India, something that is of concern to China.