Defense secretary to tour bases in North Dakota, Nebraska at heart of nuclear triad

Defense Secretary Mark Esper heads to America's heartland on Wednesday to emphasize the importance of U.S. nuclear deterrence and the need for modernization.

The defense secretary will make his first visits to Minot Air Force Base in North Dakota and Offutt Air Force Base outside Omaha, Nebraska, which is home to U.S. Strategic Command -- the combatant command responsible for the U.S. military's nuclear arsenal. Both locations serve a key purpose in maintaining America's ability to deter adversaries through the nuclear triad: strategic bombers, submarine-launched intercontinental ballistic missiles (ICBMs) and ground-based ICBMs.

However, with aging infrastructure, the Pentagon has made the modernization of the triad a priority in recent years.

Minot Air Force Base is the only base that hosts two legs of the nuclear triad, making it a unique stop for the secretary, according to the Defense Department. There, Esper will visit a missile alert facility that houses ICBMs and a launch control center to meet with missileers, maintainers and security personnel. He will also check out the nearly 60 year-old nuclear-capable B-52 bombers.

Then on Thursday, the secretary will travel to Offutt Air Force Base to meet with U.S. Strategic Command (STRATCOM) leadership and tour the highly classified Nuclear Command, Control and Communications Enterprise Center. He'll also see the newly built $1.3 billion command and control facility that STRATCOM just opened last year.

Testifying before the Senate Armed Services Committee last week, the new commander of STRATCOM, Navy Adm.Charles Richard, said he firmly supports leadership's commitment to identifying nuclear deterrence as the highest priority mission of the department.

"Our nuclear deterrent underwrites every U.S. military operation around the world and is the foundation and backstop of our national defense," Richard said. "I cannot overemphasize the need to modernize our nuclear forces and recapitalize the supporting infrastructure to ensure we can maintain this deterrent in the future. I am concerned that the oft-repeated message of the need to modernize and recapitalize has lost its impact."

In his confirmation hearing last October, Richard said the money needed to modernize the triad is minimal, only a "fraction" of the nation's discretionary budget.

"That's what buys our deterrence and defense against the only existential threat this nation faces," Richard said. "I think that is a good investment, and in the words of the former Secretary of Defense (James) Mattis: this nation can afford survival."

ABC News' Mel Madarang contributed to this report.