Mumbai: Central bank governor Sanjay Malhotra on Wednesday said it was premature to comment on market talk that the government may levy a merchant discount rate (MDR) on select UPI transactions, saying discussions are still underway on the payment mechanism that has helped replace the use of physical cash for many small-ticket transactions.The central bank's focus, he said, was on strengthening UPI adoption. "It is very premature to talk right now. The government is still carrying out the amendment," he said, while adding that the costs involved in the electronic payment mechanism would ultimately "have to be paid by someone." His remarks, in response to a query after the policy announcement, came after Finance Minister Nirmala Sitharaman introduced the Taxation and Other Laws (Amendment) Bill in Parliament on Tuesday.The Bill proposes removing restrictions that bar banks and payment service providers from levying MDR on notified electronic payment modes.