Majedi was quoted by Iran's semiofficial Fars News Agency as saying the Iranian government wasn't going to help cover the cost of building the pipeline in Pakistani territory.
"We did not make such a commitment to help Pakistan with $2 billion for the construction of the pipeline," he said Monday.
Iran has expressed concern about the project, in the planning stages for decades, because of economic uncertainty from its Pakistani counterparts.
Iranian Oil Minister Bijan Namdar Zanganeh was quoted by Fars as saying last week the nullification of the contract "for supplying gas to Pakistan is likely."
Iran's Western adversaries oppose the pipeline because of the economic benefits it would bring Tehran. Washington, in particular, favors a rival natural gas pipeline planned from Turkmenistan to help address Pakistan's energy woes.
The U.S. government warned Islamabad earlier this year the pipeline would violate sanctions targeting Iran's energy sector. Pakistani Prime Minister Nawaz Sharif told President Barack Obama during an October visit to Washington the lingering energy crisis was a "top priority" for Islamabad.