Prime Minister Yusuf Raza Gilani will lead the Pakistani delegation to the Summit at Sharm-el Shaikh on July 15, the Pakistan Foreign Office announced, a day after Singh had told mediapersons that he and Zardari would be meeting on the sidelines of the Summit.
At the start of their ice-breaking meeting at Yekaterinburg in Russia on Tuesday, Singh had told Zardari in full glare of international media that his mandate was limited to telling that Pakistan should not allow its soil to be used for terrorism against India.
It had been announced later that the foreign secretaries of the two countries would meet to discuss terrorism and then the two leaders would "take stock" of their deliberations when they meet in Sharm-el Shaikh.
Foreign Office spokesman Abdul Basit told the weekly news briefing in Islamabad on Thursday that Gilani would lead the Pakistani delegation to next month's NAM summit.
Pakistan has been represented at the last few NAM summits by former President Pervez Musharraf. Basit, however, sought to play down the development.
"We said the next meeting at Sharm el-Sheikh would be between the political leadership of the two countries. It was never said whether the President or the Prime Minister would represent Pakistan," he told PTI.
Diplomatic and other sources said the move was a reaction to Singh's remarks, which the pro-establishment daily The News had described as "rude."
They said the intention was to send out a clear message that Singh's comments had not gone down well with the Pakistan government.
The usually soft-spoken Singh caught Zardari off guard during their meeting on the sidelines of the Shanghai Cooperation Organisation in Russia on Tuesday when he told him in front of journalists that Pakistan needed to control terrorism emanating from its territory.
Apparently embarrassed, the Pakistani President told Singh that they could talk after journalists have left the hall.
Pakistan's 'The News' daily extensively covered Singh's
remarks in a report headlined "Singh surprises with rude public remark" but other sections of the media played up Foreign Minister Shah Mahmood Qureshi's comment that the meeting between Singh and Zardari was a "positive development."
The meeting between Singh and Zardari was the first high-level contact between the leadership of the two countries since last year's Mumbai terror attacks, which India blamed on Pakistan-based elements including the Lashkar-e-Tayba.
Observers said the latest development could impact Pakistan's efforts to bring composite dialogue back on track.
India put the peace process on hold in the wake of the Mumbai attacks and has linked the resumption of dialogue to Pakistan acting against perpetrators of the terrorist strike.