"No structured meeting is planned, but a pull aside is always possible," Pakistani Ambassador Shaukat Mukadam told reporters here.
"There are possibilities....there are various places to meet, they could meet in leaders` lounge," he said.
Pakistan Prime Minister Yousuf Raza Gilani is scheduled to arrive here today to attend the Summit and some reports earlier suggested that he could meet Singh.
Sources in the Pakistan government had said that Indian and Pakistani officials are in touch about arranging a meeting between Gilani and Singh.
However, Indian diplomatic sources said that the meeting of Singh and Gilani has not been scheduled yet. The summit in Seoul is a follow-up to the Nuclear Security Summit held in Washington in April 2010.
The summit is expected to be attended by 45 heads of state or governments, including US President Barack Obama, Russian President Dmitry Medvedev and Chinese President Hu Jintao.