Amari said the talks may have to be concluded within a month, but he did not give any hints on whether an agreement was likely.
"We don't have the luxury of as long as a month. I think it will be concluded within a shorter period of time," he said. "Time is running out."
The potential loss of Azadegan, tipped as one of the largest untapped oil reserves in the world, would be a blow for energy policy in resource-poor Japan, which depends on imports for almost all of its crude oil needs.
Inpex,
