The United States backs the Turkmenistan-Afghanistan-Pakistan-India natural gas option over an Iranian plan to move gas from the South Pars field in the Persian Gulf.
Pakistani Natural Resources Minister Asim Hussain said some of the parties had expressed satisfaction with a transit fee of 49.5 cents per million metric British thermal unit.
"A final round of negotiations will be held in the last week of May in Ashgabat to lock down the agreement," he was quoted by the Platts news service as saying.
A report from the Pakistani media last week said the meeting was scheduled for early May and that Afghanistan had expressed reluctance in the project.
Hussain, reports Platts, said the pricing formula discussed for TAPI could make it less expensive when compared to the Iranian pipeline.
TAPI is slated to get natural gas from the Dauletabad field in southern Turkmenistan, though Platts reports it may be sourced from its counterpart field, South Yolotan-Osman.
The pipeline could move natural gas to Pakistan as early as 2016.