The Pentagon will reportedly unveil plans later to shrink the nation's army to its smallest size since after World War Two, in a cost-cutting drive, according to BBC News.

An entire class of Air Force attack jets is tipped to be axed under plans, as Defense Secretary Chuck Hagel outlines his 2015 budget. He is expected to propose trimming the Army to about 440,000 personnel from a post-9/11 attacks peak of 570,000.

The U.S. military is under pressure to downsize after two costly foreign wars.

The number of active-duty U.S. Army members is already expected to be pared down to 490,000, as the U.S. prepares to end its combat role in Afghanistan later this year.

"We have to face the realities of our time," Pentagon press secretary Navy Rear Admiral John Kirby told the Associated Press. "We must be pragmatic, we can't escape tough choices. He and the [military service] chiefs are willing to make those choices."

According to the Wall Street Journal, Hagel will also recommend reducing housing allowances and other benefits, limiting pay raises and increasing healthcare premiums.

However, the military cost-cutting drive would probably cause ructions on Capitol Hill, which is gearing up for November's midterm elections.

The plan is said to take into account government cutbacks as well as U.S. President Barack Obama's pledge to end land wars in Iraq and Afghanistan.

"You have to always keep your institution prepared, but you can't carry a large land-war defense department when there is no large land war," a senior Pentagon official told the NYT.

Under the proposed cuts, the military would still be able to defeat any adversary, unnamed officials told that newspaper, but be too small to engage in protracted foreign occupations.