"Action on terrorism should not be linked to the composite dialogue process and these should not be bracketed," the statement said.
November's attack on Mumbai stalled a fragile peace process, launched in 2004, which was aimed at resolving a number of issues between the two neighbours, including the dispute over the divided Himalayan territory of Kashmir.
"Until Mumbai everything was going well," Saeed Naqvi, an Indian newspaper columnist, told Al Jazeera.
"But the Mumbai attack was a huge setback and then we went into the Indian elections and it was impossible for anyone to pick up such a huge hot potato at that time."
New Delhi has criticised Islambad for not handing over suspected plotters of the Mumbai attacks, which left at least 166 people dead. But this week Pakistan said that it would "probably" put the five accused of involvement in the attacks on trial shortly.
In remarks clearly addressed at Pakistan on Wednesday, Singh said that the "infrastructure of terrorism" must be dismantled.
Speaking to delegates at the summit on Wednesday, Gilani expressed some optimism over the direction that relations between the two nuclear powers were taking.
"There has recently been some forward movement in our relations with India," he said.
"We hope to sustain this momentum and move towards comprehensive engagement. We believe durable peace in South Asia is achievable."
The two nations have fought three wars, two of them over Kashmir, since they were separated in 1947 following the end of colonial British rule.
More than 50 heads of state from the developing world are in Sharm el-Sheikh for the summit which was called to tackle the impact of the global economic downturn.
"Every country in the world must seek just solutions to the global economic crisis," Raul Castro, the Cuban president, told the 118-member body on Wednesday.
"We call for a new monetary and economic world order... we must restructure the world financial system to take into consideration the needs of developing countries."
India said the body's members needed to play a bigger role on the world stage.
"Developing countries must be fully represented in the decision-making levels of international institutions," Singh said.
India, along with host Egypt, was one of the founding members of the Nam, the largest grouping of countries outside of the United Nations, which was founded in 1955 to give a voice to the developing world.