Addressing the Dhaka University on Wednesday before returning home, Manmohan Singh said, "I was hopeful that during this visit we would be able to come to an agreement on the sharing of the waters of the Teesta river."
"Both sides worked very hard to arrive at a solution that would be acceptable to all. Unfortunately these efforts did not meet their success within the time available," he said.
India and Bangladesh have not signed the Teesta accord as West Bengal Chief Minister Mamata Benerjee opposed the centre's decision to share 50 percent water with Bangladesh. She had stated that it would harm the interest of northern Bengal farmers.
During two day visit, Manmohan Singh inked many bilateral agreements between both countries on various issues, including resolving a border row where Assam has given away 600 acre of land to Bangladesh through an agreement.
PM has also asked "the concerned officials to intensify their efforts towards finding a viable formula which does not cause undue distress to all those, in India or in Bangladesh, who are dependent on the flows of the river".
The Teesta river which has its origin in Sikkim, flows through north Bengal before entering Bangladesh. India and Bangladesh have been sharing 54 rivers.