Iran's Deputy Petroleum Minister, Hadi Nejad-Husseinian, held two days of talks on the proposed $7 billion project in the Pakistani capital, Islamabad.
According to a joint statement, Pakistani Petroleum Minister Amanullah Khan Jadoon said the two sides should work in a "constructive manner" to ensure work begins by 2007.
Meanwhile, AP quoted a Pakistani government adviser on energy, Mukhtar Ahmed, as saying both parties agreed to pursue the project even if India sits out.
The project has faced opposition from the United States. But Pakistani Foreign Ministry spokesman Tasnim Aslam said his country would not bow to U.S. pressure because Pakistan needs gas to meet growing energy requirements.