Secretary of Defense Jim Mattis arrived at Stratcom at Offutt Air Force Base in Bellevue, Neb. this morning.
Mattis' stop in the Omaha-area comes a day after visiting Minot Air Force Base in North Dakota.
Mattis said he has considered reworking the current nuclear posture known as the triad: nukes launched from USAF jets, United States navy submarines, or the ground.
Mattis indicated to reporters that all three legs of the triad will stay because nuclear deterrence requires an arsenal strong enough to convince enemies that an attack would be suicidal.
"You want the enemy to look at it and say, this is impossible to take out in a first strike", said Mattis, so that they would not do so in fear of USA retaliation.More news: Explosion on London underground train, passengers suffer facial burns
Minot Air Force Base is home to two parts of the USA nuclear triad? strategic bombers and about 100 land-based intercontinental ballistic missiles (ICBM).
Minot is the only base in the United States that has both land-based missiles and strategic bombers.
Mattis also said that the key to avoiding nuclear war is maintaining a nuclear arsenal sufficient to convince a potential enemy that attacking the USA with a nuclear weapon would be suicidal.
One such enemy that has threatened nuclear war with the U.S. is of course North Korea.
The visits were scheduled prior to North Korea's sixth nuclear test earlier this month, but serve as an opportunity for Mattis to highlight the Pentagon's always-ready nuclear forces. The trip was planned before the test, but provides an opportunity to highlight the US nuclear forces.