WASHINGTON — After years in secret development, America’s newest stealth budget-buster has made its public debut as the Pentagon’s answer to calls for defense cuts after the U.S. military withdrawal from Afghanistan.

The B-21, the first new American bomber aircraft in more than 30 years, is a highly-classified long-range strike bomber capable of blowing a hole in a fiscal year or even a continuing resolution while delivering conventional and thermonuclear weapons around the globe. It will replace the B-2 Spirit and the gaping budgetary hole left by no longer needing to fund overseas contingency operations or the A-10 Warthog.

"When we talk about low observability, it is incredibly low observability," said Kathy Warden, chief executive of Northrop Grumman. "You'll hear it, but you really won't see it eat into the defense budget until it’s too late.”

The cost of the bombers is unknown, although the Air Force previously said it wanted to purchase 100 aircraft at an average cost of $550 million each in 2010 dollars — roughly $753 million today.