Due to mounting financial pressure, the U.S. Postal Service announced on Wednesday it will discontinue Saturday mail delivery.

The move, which is expected to save approximately $2 billion annually, will take effect Aug. 5.

Politicians opposed to the plan are concerned rural communities will be disproportionately harmed by the service reduction. Sen. Claire McCaskill, D-Mo., has voiced support for the U.S. Postal Service in the past, and she praised a plan announced last May that would have sacrificed office hours to preserve Saturday delivery.

Prompted by the recent announcement, McCaskill released a statement critical of Republicans for not acting to support the Postal Service, which relies on postage sales and other products to cover operational expenses.

“Instead of passing the bill, the Republicans in the U.S. House abandoned rural America and allowed the legislation to die,” McCaskill said in the statement. “And this is the result of their inaction — an unnecessary loss for business, rural families and the principle of compromise.”

McCaskill wrote to Postmaster General Patrick Donahoe on Jan. 31 requesting the Postal Service re-evaluate the anticipated cost savings and suggesting that current estimations are exaggerated.

“We don’t even know if the move to five-day delivery will save the post office any real money,” McCaskill said.

Data cited by the Postal Service in its statement pointed out the reduced demand for mail delivery as more Americans turn to the Internet, rather than paper and pen, to pay bills and keep in touch.

A survey conducted by the Postal Service in conjunction with Gallup and a handful of major newspapers, including The New York Times, USA Today and The Washington Post, indicated that 70 percent of Americans supported ending Saturday delivery in order to return the organization to financial stability.

Packages will continue to be delivered six days a week, as the Postal Service has observed a 14 percent volume increase in package delivery since 2010, fueled by the growth of online commerce.

In the 2012 plan that maintained Saturday delivery, the Postal Service said it would operate a total of 90 rural post offices across Missouri. The recent announcement did not suggest any offices would be closed, which was confirmed by Missouri Postal Service spokeswoman Valerie Welsch.

Staff members at the post office in Martinsburg, Mo., a town of 304 people approximately 35 miles northwest of Columbia, declined to comment on the issue and directed all inquiries to Welsch.

The majority of Americans support the move, but it remains to be seen how the change will affect rural communities. While the release touted the growth of package delivery and praised the Postal Service’s ability to satisfy customer needs during the recent restructuring, it also encouraged Congress to address the issue directly.

Wednesday’s statement concluded with a plea to legislators to act in support of the service.

“Legislative change is urgently needed to address matters outside the Postal Service’s control,” according to the statement. “The Postal Service … encourages the 113th Congress to make postal reform legislation an urgent priority.”