Faced with a total opposition from mobile operators on reducing roaming tariffs, regulator Trai today said it may enforce a regulation for the purpose but will first explore all options to arrive at a solution."They (operators) have expressed a point of view. I think there may be a counter point of view, which will also be shown to them...The best approach will be a resolution which is acceptable to all. So we must try up to that point before a regulation comes into the picture..The regulation should be the last resort not the first," Nripendra Misra, chairman of Trai, said after an open discussion with all stakeholders on the issue.He said TRAI would again discuss the matter with COAI and AUSPI to reach a resolution and the recommendations for the roaming tariff review are expected by the end of this month.Misra, however, seemed to agree it would be difficult to make operators agree to a further ceiling in roaming tariffs.Asked if TRAI would impose a regulation in case operators do not agree to reduce roaming tariffs, he said: "Today we have got their response and we will find out a way how we can move forward to discuss the matter with them."There is already a regulation. Operators are asking to do away with the ceiling and let this be part of forbearance. so they want a further approach of deregulation which in all regulatory regimes are possibilities. But all this must address with respect to affordability and consumers," he said.Trai has proposed to revise the existing roaming tariff by fixing a ceiling based on usage. This means there would not be any rental charges and only a composite roaming tariff on a per minute basis.