CHEYENNE, Wyo. (AP) — U.S. Sens. John Barrasso and Mike Enzi are working to maintain ground-based U.S. nuclear missile systems.

The two Wyoming Republicans joined other senators in including an amendment to legislation that urges the Obama administration to retain the Intercontinental Ballistic Missile leg of the nation's nuclear triad.The bipartisan amendment specifically calls on the U.S. Defense Department to maintain its ICBM force and preserve the silos as a reserve force.

Barrasso says further reductions in the ICBM force will compromise U.S. national security.

Enzi says the missile systems are not only cost-effective and reliable, they are a visual reminder that America stands ready to protect itself and its allies.