"Assurances from the government are not enough. We need implementation of the scheme," Hazare told the 'Run for OROP' event here, organised by retired soldiers.
He also attacked the Narendra Modi government, saying many promises were made on ending corruption but nothing had happened.
"Veterans serve the country but do not get their due," he said.
Hazare reiterated that he will launch a protest at Delhi's Ramlila Maidan on October 2, Mahatma Gandhi's birth anniversary, in support of the One Rank One Pension scheme.
"We still have two months left, and I will travel across the country to seek people's support," he added.
The 'Run for OROP' started from Dhaula Kuan in south Delhi at 6 a.m. and ended at the Jantar Mantar monument in the heart of the capital.
Retired Major D.P. Singh, who had to have his leg amputated after being injured in the 1999 Kargil conflict, led the event.
The ex-servicemen want the government to announce a date when the One Rank One Pension scheme will be implemented.
Currently, the amount of pension paid to officers of the same rank differ -- depending on when they retired.
A section of the former soldiers have been staging a relay hunger strike on the issue here since June 15.