The grouping's decision was announced by Liaquat Baloch, secretary general of the Jamaat-e-Islami and chairman of the DPC's steering committee, during a news conference here tonight.
Baloch said the long march was being postponed as Pakistan had not announced the restoration of the supply routes during the NATO Summit that concluded in Chicago on Monday.
The DPC's organising committee decided to continue the protests across the country against the NATO and US, he said.
Pakistan had closed the supply routes in November, when a cross-border NATO air strike killed 24 of its soldiers.
It had been widely expected that President Asif Ali Zardari would announce the end of the nearly six-month blockade of the supply lines at the summit in Chicago.
Jamaat-ud-Dawah leader Amir Hamza and several other DPC leaders were present at the news conference.
Baloch said the heads of organisations in the DPC will meet in Karachi on May 26 and a convention of clerics, students and workers will be held near Mazar-e-Quaid to press for the stoppage of NATO supplies.
JuD chief Hafiz Mohammad Saeed formed the DPC last year.
He recently claimed thousands of people would march to Islamabad from Karachi to force the government not to take any "pro-US decisions".