The Department of Defense has apparently decided to mothball one of its aircraft carriers, the USS Harry S. Truman, two decades early, Breaking Defense reported Wednesday.

The move, which Breaking Defense estimated could save the US Navy $30 billion over 25 years, would reduce the size of the US Navy's carrier fleet to 10.

Congress is expected to push back on plans to cancel the midlife overhaul of the Truman and retire the carrier early.

It could be an attempt to get Congress' attention, as appears to have been the case when the US military tried to retire the USS George Washington early during the Obama administration.

The Pentagon reportedly plans to send one of its Nimitz-class aircraft carriers into early retirement, shrinking the carrier fleet to save billions of dollars.

The US military is set to scrap plans for a midlife overhaul of one of its carriers, The Washington Post's David Ignatius reported Tuesday. That carrier is the USS Harry S. Truman, which was scheduled to have its nuclear reactor core refueled in 2024, Breaking Defense's Sydney Freedberg reported Wednesday.

The Truman, which entered service in 1998, was designed to serve for half a century, as is the case with all the Navy's nuclear-powered aircraft carriers. In 2024, the ship was to sail to the shipyard in Newport News, Virginia, for a refueling and complex overhaul, or RCOH, to be completed in 2028, Breaking Defense reported.

The cancelation of the midlife overhaul and retirement of the aircraft carrier — reportedly part of the 2020-24 budget plan — would see the US carrier fleet shrink in size, to 10 from 11.

While The Post estimated $4 billion in total savings, Breaking Defense said the decision might result in as much as $30 billion in savings over 25 years. The Post described it as a compromise to ensure that the Navy could purchase two new Ford-class aircraft carriers, as the service announced last month. But several questions remain.

"The decision to skip the Truman's RCOH was part of the deal to fund two new carriers," Robert Work, a former deputy defense secretary, told Breaking Defense, supporting The Post's report.

This is not the first time the US military has gone down this road, and there is a good chance that Congress will oppose the plans, especially as they would contrast with the views expressed by congressional carrier advocates and even the president.

During the Obama administration, the US military proposed retiring the USS George Washington, commissioned in 1992, to cut costs. To prevent a fight with Congress, the White House intervened, offering additional funding.

Retired Navy Capt. Jerry Hendrix told Breaking Defense that the military might be using the Truman as a "bargaining chip" for a larger budget.

Hill staffers told Breaking Defense that congressional leaders were blindsided by the decision.

The debate about the value of aircraft carriers has intensified amid the growing threat from Chinese standoff capabilities. While US carriers have long been symbols of American military might, some experts have said they are increasingly vulnerable targets rather than strategic assets.

Read more: Aircraft carriers 'are the most survivable airfield' and they may soon be even harder to kill, top Navy admiral says

The Navy, however, views the situation differently.

"Rather than expressing the carrier as uniquely vulnerable, I would say it is the most survivable airfield within the field of fire," Adm. John Richardson, the chief of naval operations, said earlier this month.