Foreign ministers of eight South Asian nations met in Bhutan's capital on Tuesday to finalise the agenda for the summit, due to be officially held on April 28 and 29.
The finance ministers from India, Pakistan Sri Lanka, Bhutan, Nepal, Afghanistan, the Maldives and Bangladesh were present.
Bhutan has chosen to focus much of the summit on climate change, because of South Asia's high vulnerability to its effects. The agenda also includes a $300 million fund for infrastructure and various projects to help reduce poverty.
The agreement on trade will cover services in areas such as health, hospitality, communications, computers and air transport.