Dwindling mail volume and a severe cash flow crisis may result in the loss of Saturday mail delivery and prompt a three-day-a-week delivery within 15 years, U.S. Postmaster General Patrick Donahoe said.

This is due to more and more people opting for electronic means of communication, instead of paper, Donahoe said, estimating that the paper-to-electronic move will result in a roughly $8.3 billion loss this year.

On Sept. 30, he told the USA TODAY editorial board Tuesday, I won't be able to pay my bills. Right now, we will have enough money to get to the end of the year. I've got a payment of $5.5 billion for the federal government to pre-fund retiree health benefits. I can't make that payment.

Mail carriers have been making rounds six days a week since the 19th century. And after postmasters discussed cutting back, Congress mandated the six-day delivery in 1983.

Not offering a timeline for the reduction in service, Donahoe said he thinks Congress, grappling with the federal budget, will be more receptive to the proposition.

With the elimination of Saturday delivery, the Postal Service wages the move would save $3.1 billion a year.

Donahoe said the idea has a much better chance today than a year ago. I don't know if I'd say 'likely' yet. Last year, a USA TODAY/Gallup Poll found that half of the people polled had no problem losing Saturday mail deliveries.

U.S. Sen. Tom Carper, D-Delaware, has introduced legislation that would permit Donahoe make the Saturday elimination. But the legislation already has one opponent in U.S. Sen. Jon Tester, D-Montana, who said losing Saturday delivery would hurt people in states likes his, where simple errands can mean long drives and mail delivery is essential.

It's important to have delivery on Saturday in places like Montana to get things like medicine and things they need, he said.